Optical apparatus

ABSTRACT

An optical apparatus uses a variable-optical-characteristic optical element whereby focusing, zooming or the like can be effected without moving a lens or the like and the whole optical apparatus can be arranged in a lightweight structure. The user wears a power transmitting unit  303  by hanging it from his/her neck, for example. The power transmitting unit  303  may be put in a clothes pocket or the like. The power transmitting unit  303  may be placed somewhere around the user. In the power transmitting unit  303 , a transmitting circuit  305  is driven by a power supply  304  to send an electromagnetic wave from a transmitting antenna  306  toward variable-focus eyeglasses  302 . The variable-focus eyeglasses  302  have a receiving antenna  307  provided on eyeglass frames  308  to receive the electromagnetic wave sent from the power transmitting unit  303 . The received electromagnetic wave is, for example, boosted in voltage and rectified to drive the variable-focus lenses.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.09/957,471, filed Sep. 21, 2001, which claims priority to Japaneseapplication nos. 2000-388165, filed Dec. 21, 2000 and 2001-009951, filedJan. 18, 2001, the entire contents of all of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to optical apparatus and, moreparticularly, to optical apparatus using avariable-optical-characteristic optical element.

Conventionally, lenses, mirrors and so forth are used in opticalapparatus. These optical elements have invariable opticalcharacteristics. That is, the focal length thereof, for example, is notvariable. Therefore, in order to effect focusing or zooming, forexample, it is necessary to move lenses, etc. This causes the wholeoptical apparatus to become unfavorably heavy in weight and large insize.

Conventional digital cameras have an arrangement in which an imagedisplay device, an imaging lens and a solid-state image pickup deviceare fixedly accommodated in a single box. Therefore, the conventionaldigital cameras have the disadvantage that they cannot be made compactand hence become unfavorably heavy. Further, because the definition(pixel density) of solid-state image pickup devices is becomingincreasingly higher, the overall functions of digital cameras rapidlybecome obsolescent. Meanwhile, there is a demand for a compact,lightweight and low-power consumption image pickup system for use inportable telephones, portable information terminals, capsule and otherendoscopes, etc. In this regard, an image pickup system using theconventional method in which an optical system consisting of lenses andother optical elements is driven by a motor is large in size and heavyin weight and suffers unfavorably high power consumption.

SUMMARY OF THE INVENTION

The present invention was made in view of the above-described problemswith the prior art.

Accordingly, an object of the present invention is to provide an opticalapparatus using a variable-optical-characteristic optical elementwhereby focusing, zooming or the like can be effected without moving alens or the like and the whole optical apparatus can be arranged in alightweight structure.

Another object of the present invention is to provide optical apparatus,e.g. a digital camera and a system using it, which are compact,lightweight and superior in function upgradability and expandability.

For example, the optical apparatus according to the present inventioninclude the following:

[1] A variable-focus lens characterized by using a piezoelectricmaterial.

[2] A variable mirror characterized by using a piezoelectric material.

[3] A variable-focus lens characterized by having a pump and a fluid.

[4] A variable mirror characterized by having a pump and a fluid.

[5] A variable-optical-characteristic optical element characterized byhaving a pump and a fluid.

[6] A variable mirror characterized by using at least two selected fromthe group consisting of electrostatic force, electromagnetic force, apiezoelectric effect, magnetostriction, a fluid pressure, an electricfield, a magnetic field, an electromagnetic wave, a temperature change,and a photomechanical effect.

[7] A variable-focus lens characterized by using at least two selectedfrom the group consisting of electrostatic force, electromagnetic force,a piezoelectric effect, magnetostriction, a fluid pressure, an electricfield, a magnetic field, an electromagnetic wave, a temperature change,and a photomechanical effect.

[8] A variable-optical-characteristic optical element characterized byusing at least two different driving methods.

[9] A variable-optical-characteristic optical element characterized byusing at least two selected from the group consisting of electrostaticforce, electromagnetic force, a piezoelectric effect, magnetostriction,a fluid pressure, an electric field, a magnetic field, anelectromagnetic wave, a temperature change, and a photomechanicaleffect.

[10] An optical device characterized by having at least twovariable-optical-characteristic optical elements driven by a fluid or ajelly-like substance, wherein the variable-optical-characteristicoptical elements are connected with each other so that the fluid orjelly-like substance is movable therebetween.

[11] An optical device as stated in the above paragraph 10, which ischaracterized in that the variable-optical-characteristic opticalelements include a variable-focus lens.

[12] An optical device as stated in the above paragraph 10, which ischaracterized in that the variable-optical-characteristic opticalelements include a variable-focus mirror.

[13] A variable-optical-characteristic optical element characterized byhaving a member for stepping up a voltage.

[14] A variable-optical-characteristic optical element as stated in theabove paragraph 13, which is characterized by using electrostatic forceor a piezoelectric effect.

[15] A variable-optical-characteristic optical element characterized byhaving a light quantity adjusting action effected by changing thelight-deflecting characteristics of an optical surface.

[16] A variable-optical-characteristic optical element characterized byhaving a light quantity adjusting action effected by changing thelight-deflecting characteristics of an optical surface to a considerableextent from a certain state where it is used.

[17] A variable-optical-characteristic optical element characterized byhaving a light quantity reducing action effected by changing thelight-deflecting characteristics of an optical surface during thetransfer operation of a solid-state image pickup device.

[18] A micropump characterized by using electrostatic force or apiezoelectric effect.

[19] A variable-optical-characteristic optical element characterized byhaving the micropump stated in the above paragraph 18.

[20] A variable mirror characterized in that a surface of an opticalelement facing the variable mirror has a curved surface configuration,and a transparent electrically conductive member is provided over thecurved surface.

[21] A variable mirror characterized in that a surface of an opticalelement facing the variable mirror has a concave surface configuration,and a transparent electrically conductive member is provided over theconcave surface.

[22] A variable mirror characterized in that a surface of an opticalelement facing the variable mirror has a convex surface configuration,and a transparent electrically conductive member is provided over theconvex surface.

[23] A variable-optical-characteristic optical element characterized byusing an organic material having piezoelectricity.

[24] A variable-optical-characteristic optical element characterized byusing a synthetic resin material having piezoelectricity.

[25] A variable-focus lens characterized by using an organic material ora synthetic resin material and being sandwiched between transparentsubstrates.

[26] A variable-focus lens characterized by using an organic materialhaving piezoelectricity or a synthetic resin material havingpiezoelectricity, wherein the variable-focus lens is sandwiched betweentransparent substrates.

[27] A variable-focus lens characterized by using an organic material ora synthetic resin material and being capable of changing theconfiguration thereof, wherein the variable-focus lens is sandwichedbetween transparent substrates.

[28] An image pickup apparatus characterized by having thevariable-optical-characteristic optical element stated in any of theabove paragraphs 15 to 17.

[29] A portable telephone characterized by having avariable-optical-characteristic optical element.

[30] A portable telephone characterized by having a variable mirror.

[31] A portable telephone characterized by having a variable-focus lens.

[32] A portable telephone characterized by having a magnificationchanging function.

[33] A portable telephone characterized by having a zooming function.

[34] A portable telephone characterized by having a focusing function.

[35] A portable telephone as stated in any of the above paragraphs 32 to34, which is characterized by having a variable mirror.

[36] A portable telephone as stated in any of the above paragraphs 32 to34, which is characterized by having a variable-focus lens.

[37] An image pickup apparatus or optical apparatus characterized byhaving a variable-optical-characteristic optical element, a free-formsurface, and a twisted optical axis.

[38] An electronic image pickup apparatus characterized by having alens, a variable-optical-characteristic optical element, a free-formsurface, and a twisted optical axis.

[39] Variable-focus eyeglasses characterized by havingvariable-optical-characteristic optical elements.

[40] Variable-focus eyeglasses characterized by havingvariable-optical-characteristic optical elements using a piezoelectricmaterial.

[41] Variable-focus eyeglasses characterized by havingvariable-optical-characteristic optical elements using a micropump.

[42] Variable-focus eyeglasses characterized by havingvariable-optical-characteristic optical elements using electrostaticforce.

[43] Variable-focus eyeglasses characterized by havingvariable-optical-characteristic optical elements using electromagneticforce.

[44] Variable-focus eyeglasses characterized by havingvariable-optical-characteristic optical elements having a fluid or ajelly-like substance.

[45] Variable-focus eyeglasses characterized by havingvariable-optical-characteristic optical elements having a fluid or ajelly-like substance and transparent electrodes.

[46] An optical apparatus characterized by having a plurality ofvariable-optical-characteristic optical elements using different drivingmethods.

[47] An optical apparatus characterized by having a plurality ofvariable-optical-characteristic optical elements using different drivingmethods, wherein the variable-optical-characteristic optical elementsare used for different functions.

[48] An optical apparatus characterized by having a plurality ofvariable mirrors using different driving methods.

[49] An optical apparatus characterized by having a plurality ofvariable-optical-characteristic optical elements using one selected fromthe group consisting of electrostatic force, electromagnetic force, apiezoelectric effect, magnetostriction, a fluid pressure, an electricfield, a magnetic field, an electromagnetic wave, and a temperaturechange, wherein the variable-optical-characteristic optical elements areused for different functions.

[50] An image pickup apparatus adapted for being mounted on a vehicle,which is characterized by having a variable-optical-characteristicoptical element.

[51] An optical system characterized in that a surface of an opticalelement facing a variable mirror has a concave surface configuration.

[52] An optical system characterized by having at least two opticalelements having extended curved surfaces, and avariable-optical-characteristic optical element.

[53] An optical system characterized by having at least two opticalelements having free-form surfaces, and a plurality ofvariable-optical-characteristic optical elements.

[54] A signal processing apparatus characterized by including avariable-optical-characteristic optical element.

[55] An information sending apparatus characterized by including avariable-optical-characteristic optical element.

[56] A remote controller characterized by including avariable-optical-characteristic optical element.

[57] A telephone characterized by including avariable-optical-characteristic optical element.

[58] A variable-optical-characteristic lens characterized in that a partof the lens is deformable by a piezoelectric effect.

[59] A variable-optical-characteristic lens characterized in that a partof a lens surface is deformable by a piezoelectric effect, and the lensdoes not have a reservoir for a fluid.

[60] A variable-optical-characteristic lens characterized by having aplurality of layers of a piezoelectric material.

[61] A variable-optical-characteristic optical element characterized byhaving a piezoelectric material consisting essentially of an organicmaterial or a synthetic resin material or an elastomer.

[62] A variable-optical-characteristic lens characterized by having apiezoelectric material consisting essentially of an organic material ora synthetic resin material or an elastomer.

[63] A variable-optical-characteristic lens characterized by having alayer of a piezoelectric material consisting essentially of an organicmaterial or a synthetic resin material or an elastomer, and a layer of atransparent member.

[64] A variable-optical-characteristic lens characterized by having apiezoelectric material consisting essentially of an organic material ora synthetic resin material or an elastomer, and a transparent memberintegrated with the piezoelectric material.

[65] A variable-optical-characteristic optical element characterized byusing a magnetostrictive material.

[66] A variable-optical-characteristic mirror characterized by using amagnetostrictive material.

[67] A variable-optical-characteristic lens characterized by using amagnetostrictive material.

[68] A variable mirror characterized by using magnetic force.

[69] A variable mirror characterized by having a ferromagnetic materialand using magnetic force.

[70] A variable-optical-characteristic optical element characterized byhaving a transparent member for protection.

[71] A variable-optical-characteristic optical element characterized byhaving a transparent member for protection in the vicinity of a surfaceon at least one side of a variable mirror or a variable-focus lens.

[72] A variable-optical-characteristic optical element characterized byusing a photomechanical effect.

[73] A variable-focus lens characterized by using a photomechanicaleffect.

[74] A variable mirror characterized by using a photomechanical effect.

[75] A variable-optical-characteristic optical element characterized byhaving at least two different kinds of light sources and using aphotomechanical effect.

[76] A contact lens characterized by using a variable-focus lens using aphotomechanical effect.

[77] Variable-focus eyeglasses characterized in that a power supply isprovided separately from variable-optical-characteristic opticalelements.

[78] Variable-focus eyeglasses characterized in that electric power issupplied thereto by an electromagnetic wave.

[79] Variable-focus eyeglasses as stated in the above paragraph 78,which are characterized by having a transmitting antenna and a receivingantenna.

[80] Variable-focus eyeglasses as stated in the above paragraph 78,which are characterized by having a receiving antenna on an eyeglassframe.

[81] Variable-focus eyeglasses as stated in the above paragraph 77 or78, which are characterized in that the power supply is placed somewherearound the user.

[82] Variable-focus eyeglasses as stated in the above paragraph 78,which are characterized in that an electromagnetic wave transmitted froma transmitting antenna is strong in a specific direction.

[83] Variable-focus eyeglasses as stated in the above paragraph 78,which are characterized by using a microwave.

[84] Variable-focus eyeglasses characterized by having a touch switch.

[85] Variable-focus eyeglasses characteristic by having a cyclic touchswitch.

[86] Variable-focus eyeglasses characterized by having an angle sensor.

[87] Variable-focus eyeglasses characterized in that refractive power ofthe eyeglasses is varied in response to a signal from an angle sensor.

[88] An optical system characterized by having avariable-optical-characteristic optical element for focusing, whereinzooming or a magnification change is effected by moving an opticalelement.

[89] An optical system characterized by having a variable mirror forfocusing, wherein zooming or a magnification change is effected bymoving an optical element.

[90] An optical system characterized by having a variable-focus lens forfocusing, wherein zooming or a magnification change is effected bymoving an optical element.

[91] An optical system characterized by using a variable mirror in whichthe short-side direction of an image pickup area is approximatelyparallel to the light-beam incidence plane of the variable mirror.

[92] An optical system characterized by using a variable mirror in whichthe short-side direction of an image pickup area is 40° or less withrespect to the light-beam incidence plane of the variable mirror.

[93] A method of controlling a variable-optical-characteristic opticalelement, which is characterized in that the amount of change of thevariable-optical-characteristic optical element is determined byreferring to values previously recorded in a storage device inaccordance with the object distance, field angle, etc.

[94] A method of controlling a variable mirror, which is characterizedin that the amount of deformation of the variable mirror is determinedby referring to values previously recorded in a storage device inaccordance with the object distance, field angle, etc.

[95] A method of controlling a variable-focus lens, which ischaracterized in that the amount of change of the variable-focus lens isdetermined by referring to values previously recorded in a storagedevice in accordance with the object distance, field angle, etc.

[96] A remote controller characterized by having avariable-optical-characteristic optical element.

[97] A cordless remote controller characterized by having avariable-optical-characteristic optical element.

[98] An automobile characterized by having avariable-optical-characteristic optical element.

[99] A viewfinder characterized by having avariable-optical-characteristic optical element.

[100] A viewfinder type display apparatus characterized by having avariable-optical-characteristic optical element.

[101] A viewfinder or viewfinder type display apparatus as stated in theabove paragraph 99 or 100, which is characterized by having a zoomingfunction.

[102] A display apparatus characterized by using avariable-optical-characteristic optical element.

[103] A video projector characterized by using avariable-optical-characteristic optical element.

[104] A signal processing apparatus characterized by using avariable-optical-characteristic optical element.

[105] A viewing apparatus characterized by using avariable-optical-characteristic optical element.

[106] A variable mirror characterized in that a surface of an opticalelement facing the variable mirror has a curved surface configuration.

[107] A variable mirror characterized in that a surface of an opticalelement facing the variable mirror has a concave surface configuration.

[108] A variable mirror characterized in that a surface of an opticalelement facing the variable mirror has a convex surface configuration.

[109] An optical apparatus characterized in that a space facing avariable-optical-characteristic optical element is closed with atransparent member and a mechanical member.

[110] An optical apparatus characterized in that a space facing avariable-optical-characteristic optical element is hermetically sealedwith a transparent member and a mechanical member.

[111] An optical apparatus as stated in the above paragraph 109, whichis characterized by using an air-permeable mechanical member ortransparent member.

[112] An optical apparatus as stated in any of the above paragraphs 109to 111, which is characterized in that thevariable-optical-characteristic optical element is a variable mirror.

[113] An optical apparatus as stated in any of the above paragraphs 109to 111, which is characterized in that thevariable-optical-characteristic optical element is a variable-focus lensor prism.

[114] Variable-focus eyeglasses characterized having a receiving antennaon an eyeglass lens, wherein electric power is supplied by anelectromagnetic wave.

[115] An optical apparatus characterized by having avariable-optical-characteristic optical element.

[116] An optical apparatus characterized by having avariable-optical-characteristic optical element to effect focusing, amagnification change or a change in the viewing direction.

[117] An image pickup apparatus adapted for being mounted on a vehicle,which is characterized by having the optical apparatus stated in theabove paragraph 116.

[118] A variable mirror characterized by using an organic piezoelectricmaterial or a synthetic resin material having piezoelectricity.

[119] A variable-optical-characteristic optical element characterized byhaving a light quantity adjusting action effected by changing theconfiguration of an optical surface to a considerable extent from acertain state where it is used.

[120] An image pickup apparatus characterized by having the opticalelement stated in the above paragraph 119.

[121] An optical apparatus characterized by having a plurality ofvariable-optical-characteristic optical elements using different drivingmethods, wherein the variable-optical-characteristic optical elementsare used at different speeds of response.

[122] An optical system characterized by having at least two opticalelements having free-form surfaces, and avariable-optical-characteristic optical element.

[123] A variable-optical-characteristic optical element characterized byrequiring electric power for operating.

[124] An electronic image pickup system including: an electronic imagepickup apparatus capable of taking an image alone; and a casing having adisplay apparatus, which is connectable with the electronic image pickupapparatus.

[125] A variable-optical-characteristic optical element using at leasttwo selected from the group consisting of electrostatic force,electromagnetic force, a piezoelectric effect, a fluid pressure, anelectric field, a magnetic field, an electromagnetic wave, and atemperature change.

[126] A portable telephone having a variable-optical-characteristicoptical element.

[127] An electronic image pickup system as stated in the above paragraph124, which is capable of taking an image even when the casing and theelectronic image pickup apparatus are connected with each other.

[128] An electronic image pickup system including: an electronic imagepickup apparatus capable of taking an image alone, which is not providedwith a display apparatus; and a casing having a display apparatus, whichis connectable with the electronic image pickup apparatus.

[129] An electronic image pickup system including: an electronic imagepickup apparatus capable of taking an image alone; and a casing having adisplay apparatus, which can be integrated with the electronic imagepickup apparatus.

[130] An electronic image pickup system including: a card-typeelectronic image pickup apparatus capable of taking an image alone; anda casing having a display apparatus, which is connectable with theelectronic image pickup apparatus.

[131] An electronic image pickup system including: a card-typeelectronic image pickup apparatus capable of taking an image alone; anda casing having a display apparatus, which can be integrated with theelectronic image pickup apparatus.

[132] An electronic image pickup system including: a card-typeelectronic image pickup apparatus capable of taking an image alone,which is not provided with a display apparatus; and a casing having adisplay apparatus, which is connectable with the electronic image pickupapparatus.

[133] An electronic image pickup system including: a box-type electronicimage pickup apparatus capable of taking an image alone; and a boxhaving a display apparatus, which is connectable with the electronicimage pickup apparatus.

[134] An electronic image pickup system including: a box-type electronicimage pickup apparatus capable of taking an image alone, which is notprovided with a display apparatus; and a box having a display apparatus,which is connectable with the electronic image pickup apparatus.

[135] An electronic image pickup apparatus connectable with a casinghaving a display apparatus and capable of taking an image either aloneor in the state of being connected with the casing.

[136] A casing having a display apparatus, which is connectable with anelectronic image pickup apparatus capable of taking an image eitheralone or in the state of being connected with the casing.

[137] An electronic image pickup apparatus connectable with a box havinga display apparatus and capable of taking an image either alone or inthe state of being connected with the box.

[138] A box having a display apparatus, which is connectable with anelectronic image pickup apparatus capable of taking an image eitheralone or in the state of being connected with the box.

[139] A card or casing having the function of each card or each casingshown in FIG. 48.

[140] A box A or box B having the function of each card or each casingshown in FIG. 48.

[141] A variable-focus lens using a piezoelectric material.

[142] A variable mirror using a piezoelectric material.

[143] A variable-focus lens having a pump and a fluid.

[144] A variable mirror having a pump and a fluid.

[145] A variable-optical-characteristic optical element having a pumpand a fluid.

[146] A variable mirror using at least two selected from the groupconsisting of electrostatic force, electromagnetic force, apiezoelectric effect, a fluid pressure, an electric field, a magneticfield, an electromagnetic wave, and a temperature change.

[147] A variable-focus lens using at least two selected from the groupconsisting of electrostatic force, electromagnetic force, apiezoelectric effect, a fluid pressure, an electric field, a magneticfield, an electromagnetic wave, and a temperature change.

[148] A variable-optical-characteristic optical element using at leasttwo different driving methods.

[149] An optical device characterized by having at least twovariable-optical-characteristic optical elements driven by a fluid or ajelly-like substance, wherein the optical elements are connected witheach other so that the fluid or jelly-like substance is movabletherebetween.

[150] An optical device as stated in the above paragraph 149, whereinthe variable-optical-characteristic optical elements include avariable-focus lens.

[151] An optical device as stated in the above paragraph 149, whereinthe variable-optical-characteristic optical elements include avariable-focus mirror.

[152] A variable-optical-characteristic optical element having a memberfor stepping up a voltage.

[153] A variable-optical-characteristic optical element as stated in theabove paragraph 152, which uses electrostatic force or a piezoelectriceffect.

[154] A variable-optical-characteristic optical element having a lightquantity adjusting action effected by changing the light-deflectingcharacteristics of an optical surface.

[155] A variable-optical-characteristic optical element having a lightquantity adjusting action effected by changing the light-deflectingcharacteristics of an optical surface to a considerable extent from acertain state where it is used.

[156] A variable-optical-characteristic optical element having a lightquantity adjusting action effected by changing the configuration of anoptical surface to a considerable extent from a certain state where itis used.

[157] A variable-optical-characteristic optical element having a lightquantity reducing action effected by changing the light-deflectingcharacteristics of an optical surface during the transfer operation of asolid-state image pickup device.

[158] A micropump using electrostatic force or a piezoelectric effect.

[159] A variable-optical-characteristic optical element having themicropump stated in the above paragraph 158.

[160] A variable mirror wherein a surface of an optical element facingthe variable mirror has a curved surface configuration, and atransparent electrically conductive member is provided over the curvedsurface.

[161] A variable mirror wherein a surface of an optical element facingthe variable mirror has a concave surface configuration, and atransparent electrically conductive member is provided over the concavesurface.

[162] A variable mirror wherein a surface of an optical element facingthe variable mirror has a convex surface configuration, and atransparent electrically conductive member is provided over the convexsurface.

[163] A variable-optical-characteristic optical element using an organicmaterial having piezoelectricity.

[164] A variable-optical-characteristic optical element using asynthetic resin material having piezoelectricity.

[165] A variable-focus lens using an organic material or a syntheticresin material and being sandwiched between transparent substrates.

[166] A variable-focus lens using an organic material havingpiezoelectricity or a synthetic resin material having piezoelectricity,wherein the variable-focus lens is sandwiched between transparentsubstrates.

[167] A variable-focus lens using an organic material or a syntheticresin material and being capable of changing the configuration thereof,wherein the variable-focus lens is sandwiched between transparentsubstrates.

[168] An optical apparatus having a variable-optical-characteristicoptical element.

[169] An image pickup apparatus having thevariable-optical-characteristic optical element stated in one of theabove paragraphs 154 to 157.

[170] A portable telephone having a variable mirror.

[171] A portable telephone having a variable-focus lens.

[172] A portable telephone having a magnification changing function.

[173] A portable telephone having a zooming function.

[174] A portable telephone having a focusing function.

[175] A portable telephone as stated in the above paragraphs 172 to 174,which has a variable mirror.

[176] A portable telephone as stated in the above paragraphs 172 to 174,which has a variable-focus lens.

[177] An image pickup apparatus or optical system having avariable-optical-characteristic optical element, a free-form surface,and a twisted optical axis.

[178] An electronic image pickup apparatus or optical apparatus having alens, a variable-optical-characteristic optical element, a free-formsurface, and a twisted optical axis.

[179] Variable-focus eyeglasses having variable-optical-characteristicoptical elements.

[180] Variable-focus eyeglasses having variable-optical-characteristicoptical elements using a piezoelectric material.

[181] Variable-focus eyeglasses having variable-optical-characteristicoptical elements using a micropump.

[182] Variable-focus eyeglasses having variable-optical-characteristicoptical elements using electrostatic force.

[183] Variable-focus eyeglasses having variable-optical-characteristicoptical elements using electromagnetic force.

[184] Variable-focus eyeglasses having variable-optical-characteristicoptical elements having a fluid or a jelly-like substance.

[185] Variable-focus eyeglasses having variable-optical-characteristicoptical elements having a fluid or a jelly-like substance andtransparent electrodes.

[186] An optical apparatus having a plurality ofvariable-optical-characteristic optical elements using different drivingmethods.

[187] An optical apparatus having a plurality ofvariable-optical-characteristic optical elements using different drivingmethods, wherein the variable-optical-characteristic optical elementsare used for different functions.

[188] An optical apparatus having a plurality ofvariable-optical-characteristic optical elements using different drivingmethods, wherein the variable-optical-characteristic optical elementsare used at different speeds of response.

[189] An optical apparatus having a plurality of variable mirrors usingdifferent driving methods.

[190] An optical apparatus having a plurality ofvariable-optical-characteristic optical elements using one selected fromthe group consisting of electrostatic force, electromagnetic force, apiezoelectric effect, magnetostriction, a fluid pressure, an electricfield, a magnetic field, an electromagnetic wave, and a temperaturechange, wherein the variable-optical-characteristic optical elements areused for different functions.

[191] An image pickup apparatus adapted for being mounted on a vehicle,which has a variable-optical-characteristic optical element.

[192] An image pickup apparatus adapted for being mounted on a vehicle,which has a variable-focus mirror to effect focusing, zooming or achange in the viewing direction.

[193] An optical apparatus wherein a surface of an optical elementfacing a variable mirror has a concave surface configuration.

[194] An optical system having at least two optical elements havingextended curved surfaces, and a variable-optical-characteristic opticalelement.

[195] An optical apparatus having at least two optical elements havingfree-form surfaces, and a variable-optical-characteristic opticalelement.

[196] An optical apparatus having at least two optical elements havingfree-form surfaces, and a plurality of variable-optical-characteristicoptical elements.

[197] A display apparatus using a variable-optical-characteristicoptical element.

[198] A video projector using a variable-optical-characteristic opticalelement.

[199] A signal processing apparatus using avariable-optical-characteristic optical element.

[200] A viewing apparatus using a variable-optical-characteristicoptical element.

[201] A signal processing apparatus including avariable-optical-characteristic optical element.

[202] An information sending apparatus including avariable-optical-characteristic optical element.

[203] A remote controller including a variable-optical-characteristicoptical element.

[204] A telephone including a variable-optical-characteristic element.

[205] A variable-optical-characteristic optical element wherein atransparent member for protection is provided at least one side of thevariable-optical-characteristic optical element.

[206] A variable mirror using an organic piezoelectric material or asynthetic resin material having piezoelectricity.

Still other objects and advantages of the invention will in part beobvious and will in part be apparent from the specification.

The invention accordingly comprises the features of construction,combinations of elements, and arrangement of parts which will beexemplified in the construction hereinafter set forth, and the scope ofthe invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram for describing the arrangement and operation of anexample of a variable-focus lens for use in an optical product accordingto the present invention, which uses electrostatic force.

FIG. 2 is a diagram for describing the arrangement and operation of anexample of a variable-focus lens for use in an optical product accordingto the present invention, which uses a transparent piezoelectric resinmaterial.

FIG. 3 is a diagram showing the arrangement of an example of the opticalapparatus according to the present invention.

FIG. 4 is a diagram showing another embodiment of the variable mirrorshown in FIG. 3.

FIG. 5 is a diagram showing an arrangement in which electrodes aredivided concentrically.

FIG. 6 is a diagram showing an arrangement in which electrodes aredivided rectangularly.

FIG. 7 is a diagram showing a further embodiment of the variable mirror.

FIG. 8 is a diagram showing a further embodiment of the variable mirror.

FIG. 9 is a diagram showing a further embodiment of the variable mirror.

FIG. 10 is a diagram showing a further embodiment of the variablemirror.

FIG. 11 is a diagram showing the way in which the winding density of athin-film coil varies according to the position.

FIG. 12 is a diagram showing an arrangement using a single coil.

FIG. 13 is a diagram showing a further embodiment of the variablemirror.

FIG. 14 is a diagram showing another example of the arrangement ofcoils.

FIG. 15 is a diagram showing another example of the arrangement ofcoils.

FIG. 16 is a diagram showing the arrangement of permanent magnets in theembodiment shown in FIG. 9.

FIG. 17 is a diagram showing the arrangement of one embodiment of animage pickup unit using a variable-focus lens according to the presentinvention.

FIG. 18 is a diagram for describing the arrangement and operation of anembodiment of a variable-focus lens having the same arrangement as thatshown in FIG. 17 except that the cylinder is omitted.

FIG. 19 is a diagram showing the arrangement of an embodiment of avariable-focus lens according to the present invention in which a fluidis forced in and out by a micropump.

FIG. 20 is a diagram showing the arrangement of an example of themicropump.

FIG. 21 is a diagram showing the arrangement of an embodiment of avariable mirror according to the present invention that uses a fluidpump.

FIG. 22 is a diagram showing the arrangement of an embodiment of avariable-focus lens according to the present invention that isdeformable by a piezoelectric effect.

FIG. 23 is a diagram showing the arrangement of an embodiment of avariable mirror according to the present invention that uses amagnetostrictive material.

FIG. 24 is a diagram showing the arrangement of an embodiment of avariable-focus lens according to the present invention that uses apiezoelectric material.

FIG. 25 is a diagram showing the arrangement of a modification of theembodiment of the variable-focus lens shown in FIG. 24.

FIG. 26 is a diagram showing the arrangement of an embodiment of avariable-focus lens according to the present invention that uses twothin films of a piezoelectric material.

FIG. 27 is a diagram showing the arrangement of an embodiment of avariable-focus lens according to the present invention that uses anelectrostrictive material.

FIG. 28 is a diagram showing the way in which the variable-focus lensshown in FIG. 27 is deformed.

FIG. 29 is a diagram showing the arrangement of an embodiment of avariable-focus lens according to the present invention that uses aphotomechanical effect.

FIG. 30 is a diagram showing the state change of trans-form azobenzene.

FIG. 31 is a schematic view showing an example of an image pickup systemusing a variable mirror according to the present invention.

FIG. 32 is a perspective view showing the arrangement of an embodimentof variable-focus eyeglasses using variable-focus lenses according tothe present invention.

FIG. 33 is a diagram showing the way in which a user wears thevariable-focus eyeglasses shown in FIG. 32.

FIG. 34 is a diagram showing the arrangement of an embodiment ofvariable-focus eyeglasses using variable-focus lenses according to thepresent invention.

FIG. 35 is a diagram showing the arrangement of an embodiment of anoptical system for a zoom digital camera using a variable mirroraccording to the present invention.

FIG. 36 is a diagram showing the arrangement of an embodiment of a zoomoptical system using a variable-focus lens according to the presentinvention.

FIG. 37 is a schematic view showing an electronic image pickup apparatususing a variable mirror according to the present invention.

FIG. 38 is a diagram illustrating a state of the variable mirror used inthe embodiment shown in FIG. 37.

FIG. 39 is a diagram illustrating a modification of the variable mirrorused in the embodiment shown in FIG. 37.

FIG. 40 is a schematic view showing an embodiment of a variable-focuslens arranged to operate also as a shutter or a stop.

FIG. 41 is a diagram showing the arrangement of an embodiment of a videocamera adapted for being mounted on a vehicle, which uses twovariable-optical-characteristic optical elements operated by differentdriving methods according to the present invention.

FIG. 42 is a diagram showing the way in which the video camera shown inFIG. 41 is mounted on an automobile, by way of example.

FIG. 43 is a diagram showing the way in which the video camera shown inFIG. 41 is mounted on a remote controller for a television.

FIG. 44 is a diagram showing the arrangement of an embodiment of aviewfinder type display apparatus using a variable mirror according tothe present invention.

FIG. 45 is a perspective view showing a PDA equipped with a viewfindertype display apparatus such as that shown in FIG. 44.

FIG. 46 is a fragmentary perspective view showing a digital cameraaccording to an embodiment of the optical apparatus of the presentinvention that is in one state of being used for photography.

FIG. 47 is a perspective view showing the digital camera according tothe embodiment in FIG. 46 that is in another state of being used forphotography.

FIG. 48 is a diagram showing a system of optical apparatus according tothe present invention that is applicable to the embodiment shown in FIG.46.

FIG. 49 is a diagram illustrating the way in which a paper displaycasing and a card-type digital camera are combined together.

FIG. 50 is a diagram illustrating an embodiment of a compound-eye thintype card.

FIG. 51 is a perspective view showing another embodiment of the opticalapparatus according to the present invention.

FIG. 52 is a schematic view showing still another embodiment of theoptical apparatus according to the present invention.

FIG. 53 is a diagram illustrating variable-focus eyeglasses usingvariable-focus lenses according to a further embodiment of the opticalapparatus of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the optical apparatus according to the present inventionwill be described below.

FIG. 1 is a diagram for describing the arrangement and operation of anexample of a variable-focus lens 62 for use in an optical productaccording to the present invention, which uses electrostatic force. Atransparent member 60 is deformable under application of a voltage. Thedeformation of the transparent member 60 causes a change in theconfiguration of the lens, thereby allowing a variable-focus system tobe realized. In FIG. 1, reference numeral 59 denotes transparentelectrodes, and reference numeral 161 denotes a transparent fluid.Further, reference numeral 163 denotes a transparent substrate, andreference numeral 168 denotes a fluid reservoir. The transparentsubstrate 163 and the transparent member 60 are positioned to face eachother. The transparent electrodes 59 are provided on the respectiveinner sides of the transparent substrate 163 and the transparent member60. The space between the transparent electrodes 59 is filled with thetransparent fluid 161 from the fluid reservoir 168. The transparentmember 60 is deformed by varying the voltage applied between thetransparent electrodes 59, thereby allowing the lens configuration to bechanged.

FIG. 2 is a diagram for describing the arrangement and operation of anexample of a variable-focus lens 56 for use in an optical productaccording to the present invention, which uses a transparentpiezoelectric resin material. Transparent electrodes 59 are cemented toboth sides of a soft transparent substance 143 having piezoelectricity.When a voltage is applied between the transparent electrodes 59, thetransparent substance 143 is deformed by the piezoelectric effect,thereby allowing a variable-focus system to be realized. Thus, thetransparent substance 143 is deformed by varying the voltage appliedbetween the transparent electrodes 59, thereby allowing the lensconfiguration to be changed.

In the case of FIG. 1, the configuration of the variable-focus lens 62is changed by using electrostatic force. However, electromagnetic forcemay be used in place of electrostatic force. In this regard, a referenceshould be made to the following examples of variable mirrors.

Next, variable mirrors will be described.

FIG. 3 is a diagram showing the arrangement of an example of the opticalapparatus according to the present invention. The figure shows anexample of a Keplerian viewfinder for a digital camera that uses avariable-optical-characteristic mirror 9. It is a matter of course thatthe illustrated optical apparatus is also usable in a silver halidefilm-with-lens camera. First, the variable-optical-characteristic mirror9 will be described.

The variable-optical-characteristic mirror (hereinafter referred to assimply “variable mirror”) 9 comprises an aluminum-coated thin film(reflecting surface) 9 a and a plurality of electrodes 9 b. A pluralityof variable resistors 11 are connected to the electrodes 9 b,respectively. A power supply 12 is connected between the thin film 9 aand the electrodes 9 b through the variable resistors 11 and a powerswitch 13. A computing unit 14 controls the resistance values of thevariable resistors 11. A temperature sensor 15, a humidity sensor 16 anda distance sensor 17 are connected to the computing unit 14. Thesemembers are arranged as shown in the figure to constitute one opticalapparatus.

It should be noted that each of the surfaces of an objective lens 902,ocular lens 901, prism 4, isosceles rectangular prism 5, mirror 6 andvariable mirror 9 need not be plane surfaces but may have anyconfiguration, e.g. a spherical surface, a rotationally symmetricaspherical surface, a spherical surface decentered with respect to anoptical axis, a plane surface decentered with respect to an opticalaxis, a rotationally symmetric aspherical surface decentered withrespect to an optical axis, an aspherical surface having planes ofsymmetry, an aspherical surface having only one plane of symmetry, anaspherical surface having no plane of symmetry, a free-form surface, ora surface having non-differentiable points or lines. The surfaces may beany surfaces that can have some effect on light, whether reflectingsurfaces or refracting surfaces. These surfaces will hereinafter begenerically called “extended curved surfaces”.

The thin film 9 a is adapted to be deformed by electrostatic force whena voltage is applied between the plurality of electrodes 9 b so that thesurface configuration thereof is changed as in the case of membranemirrors described, for example, in Handbook of Microlithography,Micromachining and Microfabrication, Volume 2: Micromachining andMicrofabrication, P. 495, Fig. 8.58, compiled by P. Raichoudhury, SPIEPRESS, and Optics Communications, Vol. 140 (1997), p. 187-190. Thus, itis possible to effect focusing in accordance with the diopter of theobserver. In addition, the thin film 9 a suppresses degradation inimage-forming performance caused by deformation or variations inrefractive index of the lenses 901 and 902 and/or the prism 4, theisosceles rectangular prism 5 and the mirror 6 or expansion, contractionor deformation of the lens frames due to changes in temperature andhumidity and assembling errors of components such as optical elementsand frames, thereby making it possible to effect focusing correctly andto correct aberrations arising from the focusing at all times.

Regarding the configuration of the electrodes 9 b, any appropriateconfiguration should be selected in accordance with the way in which thethin film 9 a is deformed, as shown in FIG. 5 or 6 by way of example.

According to this embodiment, light from an object is refracted by theentrance and exit surfaces of the objective lens 902 and the prism 4 andreflected by the variable mirror 9. The reflected light passes throughthe prism 4 and is reflected by the isosceles rectangular prism 5 (inFIG. 3, the mark+in the optical path indicates that light rays traveltoward the reverse side of the plane of the figure). The reflected lightis further reflected by the mirror 6 to enter the eye through the ocularlens 901. Thus, the lenses 901 and 902, the prisms 4 and 5, and thevariable mirror 9 constitute a viewing optical system of the opticalapparatus according to this embodiment. By optimizing the surfaceconfigurations and thicknesses of these optical elements, it is possibleto minimize aberrations of the object image.

That is, the configuration of the thin film 9 a, which serves as areflecting surface, is controlled by changing the resistance value ofeach variable resistor 11 on the basis of a signal from the computingunit 14 so that the image-forming performance is optimized. Morespecifically, the computing unit 14 is supplied with input signalshaving magnitudes corresponding to the ambient temperature and humidityand the distance to the object from the temperature sensor 15, thehumidity sensor 16 and the distance sensor 17. On the basis of theseinput signals, the computing unit 14 outputs a signal for determiningthe resistance values of the variable resistors 11 so that such avoltage is applied to each of the electrodes 9 b that the configurationof the thin film 9 a is determined so as to compensate for degradationin image-forming performance due to the ambient temperature and humidityconditions and the distance to the object. Thus, the thin film 9 a isdeformed by the voltage applied to each of the electrodes 9 b, that is,electrostatic force. Therefore, the thin film 9 a assumes variousconfigurations, including an aspherical surface, according tocircumstances. If the polarity of the applied voltage is changed, thethin film 9 a can be deformed into a convex surface. It should be notedthat the distance sensor 17 may be omitted. In such a case, an imaginglens 3 of the digital camera is moved so that the high-frequencycomponent of the image signal from a solid-state image pickup device 8substantially reaches a maximum. From this position, the object distanceis calculated in reverse manner, and the variable mirror is deformed sothat focusing is effected with respect to the observer's eye.

If the thin film 9 a is produced from a synthetic resin material, e.g. apolyimide, the thin film 9 a can be deformed to a considerable extentwith a low voltage, advantageously. It should be noted that the prism 4and the variable mirror 9 can be integrally formed into one unit, andthis unit is an example of the optical apparatus according to thepresent invention.

Although not shown in the figure, the solid-state image pickup device 8may be integrally formed on the substrate of the variable mirror 9 by alithography process.

If the lenses 901 and 902, the prisms 4 and 5, and the mirror 6 areformed by plastic molding or the like, curved surfaces of desiredconfigurations can be readily formed at will, and the production isfacilitated. Although in the image pickup apparatus according to thisembodiment the lenses 901 and 902 are formed away from the prism 4, ifthe prisms 4 and 5, the mirror 6 and the variable mirror 9 are designedso that aberrations can be removed without providing the lenses 901 and902, the prisms 4 and 5 and the variable mirror 9 are constructed in theform of a single optical block. Accordingly, the assembly isfacilitated. Some or all of the optical elements, i.e. the lenses 901and 902, the prisms 4 and 5, and the mirror 6, may be made of glass. Bydoing so, an image pickup apparatus with a higher degree of accuracy canbe obtained.

In the example shown in FIG. 3, the computing unit 14, the temperaturesensor 15, the humidity sensor 16 and the distance sensor 17 areprovided, and temperature and humidity changes and a change in theobject distance are compensated for by the variable mirror 9. However,the present invention is not necessarily limited thereto. That is, thearrangement may be such that the computing unit 14, the temperaturesensor 15, the humidity sensor 16 and the distance sensor 17 areomitted, and only a change in the diopter of the observer is compensatedfor by the variable mirror 9.

Next, the arrangement of the variable mirror 9 will be described.

FIG. 4 shows another embodiment of the variable mirror 9. In thisembodiment, a piezoelectric element 9 c is interposed between the thinfilm 9 a and the electrodes 9 b, and these members are provided on asupport plate 23. By changing the voltage applied to the piezoelectricelement 9 c for each electrode 9 b, the piezoelectric element 9 c iscaused to have expansion or contraction varying from region to region,thereby allowing the configuration of the thin film 9 a to be changed.Regarding the configuration of the electrodes 9 b, the electrodes 9 bmay be concentrically divided as shown in FIG. 5 or rectangularlydivided as shown in FIG. 6. In addition, it is possible to select anyappropriate configuration. Reference numeral 24 denotes a shake (blur)sensor connected to the computing unit 14. The shake sensor 24 senses ashake at the time of photographing with a digital camera, for example,and causes the voltage applied to the electrodes 9 b to be changedthrough the computing unit 14 and the variable resistors 11 to deformthe thin film 9 a so as to compensate for disorder of the image due tothe shake. At this time, signals from the temperature sensor 15, thehumidity sensor 16 and the distance sensor 17 are also simultaneouslytaken into consideration, and thus focusing, temperature and humiditycompensation, etc. are performed. In this case, the thin film 9 a issubjected to stress accompanying the deformation of the piezoelectricelement 9 c. Therefore, the thin film 9 a should preferably be madethick to a certain extent so as to have appropriate strength.

FIG. 7 shows a further embodiment of the variable mirror 9. Thisembodiment differs from the embodiment shown in FIG. 4 in that apiezoelectric element interposed between the thin film 9 a and theelectrodes 9 b comprises two piezoelectric elements 9 c and 9 c′ made ofrespective materials having piezoelectric characteristics opposite indirection to each other. That is, if the piezoelectric elements 9 c and9 c′ are made of ferroelectric crystals, the crystals are disposed sothat the directions of the crystal axes are opposite to each other. Inthis case, when a voltage is applied thereto, the piezoelectric elements9 c and 9 c′ expand or contract in opposite directions. Therefore, forcefor deforming the thin film 9 a is stronger than in the case of theexample shown in FIG. 4. Consequently, the configuration of the mirrorsurface can be changed to a considerable extent, advantageously.

Examples of materials usable for the piezoelectric elements 9 c and 9 c′include piezoelectric substances, i.e. barium titanate, Rochelle salt,rock crystal, tourmaline, potassium dihydrogenphosphate (KDP), ammoniumdihydrogenphosphate (ADP), and lithium niobate, polycrystals of thepiezoelectric substances, crystals of the piezoelectric substances,piezoelectric ceramics comprising a solid solution of PbZrO₃ and PbTiO₃,organic piezoelectric substances, i.e. polyvinyl difluoride (PVDF), andother ferroelectric materials. Organic piezoelectric substances areparticularly preferable because they have a small Young's modulus andare deformable to a considerable extent with a low voltage. It should benoted that when these piezoelectric elements are used, if the thicknessthereof is made non-uniform, the configuration of the thin film 9 a canbe changed appropriately in the above-described embodiment.

FIG. 8 shows a further embodiment of the variable mirror 9. In thisembodiment, the piezoelectric element 9 c is sandwiched between the thinfilm 9 a and an electrode 9 d, and a voltage is applied between the thinfilm 9 a and the electrode 9 d through a driving circuit 25 controlledby the computing unit 14. In addition to this, a voltage is applied toeach of the electrodes 9 b provided on the support plate 23 through eachdriving circuit 25 controlled by the computing unit 14. Accordingly, inthis embodiment the thin film 9 a can be deformed double by thepiezoelectric effect produced by the voltage applied between it and theelectrode 9 d and electrostatic force produced by the voltage applied toeach electrode 9 b. Thus, the thin film 9 a can provide a larger numberof deformation patterns and exhibit faster response than any of thoseshown in the foregoing embodiments, advantageously.

If the sign of the voltage applied between the thin film 9 a and theelectrode 9 d is changed, the variable mirror can be deformed intoeither a convex surface or a concave surface. The arrangement may besuch that a large deformation is made by the piezoelectric effect, and asmall configuration change is effected by the electrostatic force. It isalso possible to use the piezoelectric effect mainly for the deformationof the variable mirror into a convex surface and to use theelectrostatic force mainly for the deformation of the variable mirrorinto a concave surface.

It should be noted that the electrode 9 d may be formed from a pluralityof electrodes as in the case of the electrodes 9 b. The way in which theelectrode 9 d comprises a plurality of electrodes is shown in FIG. 8. Itshould be noted that, in this specification, piezoelectric effect,electrostriction and electrostrictive effect are generically called“piezoelectric effect”. Accordingly, electrostrictive materials shallalso be included in piezoelectric materials.

In a case where an electrostrictive material is used as thepiezoelectric element 9 c, it is possible to form the piezoelectricelement 9 c in a structure in which the electrostrictive material and adeformable substrate are integrated together.

FIG. 9 shows a further embodiment of the variable mirror 9. Thisembodiment utilizes electromagnetic force to allow the configuration ofa reflecting surface to be changed. A permanent magnet 26 is provided onthe inner bottom surface of a support plate 23, and the peripheral edgeportion of a substrate 9 e made of silicon nitride or a polyimide isplaced on and secured to the top of the support plate 23. The surface ofthe substrate 9 e is provided with a thin film 9 a formed from a metalcoating, e.g. aluminum, to form a variable mirror 9. A plurality ofcoils 27 are provided on the lower side of the substrate 9 e. The coils27 are connected to the computing unit 14 through respective drivingcircuits 28. Accordingly, when an appropriate electric current issupplied to each coil 27 from the associated driving circuit 28according to an output signal from the computing unit 14 correspondingto changes in the optical system obtained by the computing unit 14 onthe basis of signals from the sensors 15, 16, 17 and 24, each coil 27 isrepelled or attracted by electromagnetic force acting between it and thepermanent magnet 26, causing the substrate 9 e and the thin film 9 a tobe deformed.

In this case, the coils 27 may be supplied with different amounts ofelectric current. The number of coils 27 may be one. The arrangement maybe such that the permanent magnet 26 is provided on the substrate 9 eand the coils 27 are provided on the inner bottom surface of the supportplate 23. The coils 27 should preferably be formed by lithography orother similar technique. Further, a core made of a ferromagneticmaterial may be inserted into each coil 27.

FIG. 10 shows a further embodiment of the variable mirror 9. In thisembodiment, a thin-film coil 28′ is provided on the lower surface of thesubstrate 9 e, and coils 27 are provided on the inner bottom surface ofthe support plate 23 to face the thin-film coil 28′. The thin-film coil28′ is connected with a variable resistor 11, a power supply 12 and apower switch 13 to supply an appropriate electric current theretoaccording to need. Each coil 27 is connected with a variable resistor11. In addition, a power supply 12 is provided to supply an electriccurrent to the coils 27 and the variable resistors 11, and a switch 29serving as both a selector switch and a power on/off switch is providedto change the direction of electric current flowing through the coils27. Therefore, according to this embodiment, by changing the resistancevalue of each variable resistor 11, electromagnetic force acting betweeneach coil 27 and the thin-film coil 28′ is varied, and thus thesubstrate 9 e and the thin film 9 a are deformed. In this way, the thinfilm 9 a can be operated as a variable mirror. By reversing the switch29 so as to change the direction of electric current flowing through thecoils 27, the thin film 9 a can be changed into either a concave surfaceor a convex surface.

In this case, it is also possible to deform the substrate 9 e and thethin film 9 a as desired by varying the winding density of the thin-filmcoil 28′ according to the position, as shown in FIG. 11. As shown inFIG. 12, the number of coils 27 may be one. Further, a core made of aferromagnetic material may be inserted into each coil 27. If a magneticfluid is filled into a space formed by the support plate 23, theelectromagnetic force becomes stronger.

FIG. 13 shows a further embodiment of the variable mirror 9. In thisexample, a substrate 9 e is made of a ferromagnetic material, e.g. iron,and a thin film 9 a as a reflecting film is made of aluminum or thelike. In this case, a thin-film coil need not be provided. Therefore,the structure is simple in comparison to the example shown in FIG. 10,for example, and the production cost can be reduced. If the power switch13 is replaced with the switch 29 serving as both a selector switch anda power on/off switch (see FIG. 10), it is possible to change thedirection of electric current flowing through the coils 27 and to freelychange the configuration of the stack of the substrate 9 e and the thinfilm 9 a. FIG. 14 shows the arrangement of the coils 27 in this example,and FIG. 15 shows another example of the arrangement of the coils 27.These arrangements are also applicable to the examples shown in FIGS. 9and 10. It should be noted that FIG. 16 shows an arrangement ofpermanent magnets 26 that is suitable in a case where in the exampleshown in FIG. 9 the coils 27 are arranged as shown in FIG. 15. That is,if the permanent magnets 26 are radially arranged as shown in FIG. 16,the substrate 9 e and the thin film 9 a can be deformed even moredelicately than in the embodiment shown in FIG. 9. In addition, in acase where the substrate 9 e and the thin film 9 a are deformed by usingelectromagnetic force in this way (the embodiments shown in FIGS. 9, 10and 13), they can be driven at a lower voltage than in the case of usingelectrostatic force, advantageously.

In the foregoing, some examples of variable mirrors have been described.To deform such a mirror, two or more different kinds of force may beused as in the example shown in FIG. 8. That is, a variable mirror canbe deformed by simultaneously using two or more selected from the groupconsisting of electrostatic force, electromagnetic force, apiezoelectric effect, magnetostriction, a fluid pressure, an electricfield, a magnetic field, a temperature change, an electromagnetic wave,etc. In other words, if a variable-optical-characteristic opticalelement is formed by using two or more different driving methods, alarge deformation and a small deformation can be realizedsimultaneously. Accordingly, it is possible to realize a mirror surfacewith a high degree of accuracy. This idea is also applicable tovariable-focus lenses described below.

FIG. 17 is a diagram showing the arrangement of a further example of thepresent invention. The figure shows an example of an image pickup unit141 using a variable-focus lens 140. A combination of a convex lens 102and the variable-focus lens 140 forms an imaging lens. The imaging lensis combined with a solid-state image pickup device 8 to form an imagepickup unit.

The variable-focus lens 140 has a transparent member 142 and a softtransparent substance 143 having piezoelectricity, e.g. a syntheticresin material. The transparent member 142 and the transparent substance143 sandwich a light-transmitting fluid or jelly-like substance 144therebetween. Examples of substances usable as the fluid or jelly-likesubstance 144 are silicone oil, elastic rubber, jelly, and water.

Transparent electrodes 145 are provided on both sides of the softtransparent substance 143. When a predetermined voltage is appliedbetween the transparent electrodes 145 from an electronic circuit 103,the soft transparent substance 143 is deformed by the piezoelectriceffect thereof, causing the focal length of the variable-focus lens 140to be changed. Accordingly, even when the object distance has changed,focusing can be effected without moving the optical system by a motor orthe like. Thus, the image pickup unit 141 is excellent in that thestructure is compact and lightweight and the power consumption isfavorably small. It should be noted that reference numeral 146 in FIG.17 denotes a cylinder for storing the fluid or jelly-like substance 144.It should be noted that examples of materials usable as the softtransparent substance 143 having piezoelectricity are polymerpiezoelectric materials, e.g. polyurethane, silicone rubber, acrylicelastomer, PZT, PLZT, and polyvinylidene fluoride (PVDF), andcopolymers, e.g. vinylidene cyanide copolymer, and a vinylidenefluoride-trifluoroethylene copolymer.

In a case where an electrostrictive material, e.g. acrylic elastomer orsilicone rubber, is used as the soft transparent substance 143, it ispossible to form the soft transparent substance 143 in a structure inwhich a transparent substrate and an electrostrictive material arecemented together.

It is preferable to use an organic material having piezoelectricity, asynthetic resin material having piezoelectricity, an elastomerexhibiting piezoelectricity, etc. The use of such a material makes itpossible to realize a large deformation of the variable-focus lenssurface. It should be noted that a transparent piezoelectric materialshould preferably be used for the variable-focus lens 140, as a matterof course.

These materials are also usable for variable mirrors using apiezoelectric effect. The use of such materials allows realization ofvariable mirrors capable of being deformed to a considerable extent.

In the example shown in FIG. 17, the cylinder 146 may be omitted. Thatis, the variable-focus lens 140 may have a structure in which thecylinder 146 is omitted, as shown in part (a) of FIG. 18. In this case,support members 147 secure certain peripheral portions of the softtransparent substance 143 having piezoelectricity. Even when thetransparent substance 143 is deformed, as shown in part (b) of FIG. 18,under application of a voltage to the soft transparent substance 143,the deformation causes no change in the volumetric capacity of thevariable-focus lens 140. Therefore, the cylinder 146 is unnecessary.Reference numeral 148 denotes deformable members made of an elasticmaterial or an accordion-shaped synthetic resin or metallic material.

The electronic circuit 103 may include a booster circuit. It ispreferable to form the booster circuit by using a piezoelectrictransformer or the like from the viewpoint of realizing a compactstructure. The booster circuit is usable for all thevariable-optical-characteristic optical elements in the presentinvention.

In the examples shown in FIGS. 17 and 18, if the voltage is appliedinversely, the soft transparent substance 143 having piezoelectricity isdeformed in the opposite direction. Therefore, the variable-focus lens140 can be formed into a concave lens.

FIG. 19 is a diagram showing another example of the variable-focuslenses. The figure shows an example of a variable-focus lens 162 inwhich a fluid 161 is forced in and out by micropumps 160, therebydeforming the lens surface. The micropumps 160 are small-sized pumpsproduced by micromachine techniques, for example, which operate onelectric power. The fluid 161 is sandwiched between a transparentsubstrate 163 and an elastic material 164. Reference numeral 165 denotesa transparent substrate for protecting the elastic material 164. Thetransparent substrate 165 may be omitted. Examples of the pumps 160produced by micromachine techniques include micropumps utilizing thermaldeformation, micropumps using a piezoelectric material, and micropumpsusing electrostatic force. The transparent substrate 165 may be a lens.It should be noted that reference numeral 400 in the figure denotesspacers.

FIG. 20 is a diagram showing the arrangement of a micropump 180 as anexample. A diaphragm 181 vibrates on electric power by the action ofelectrostatic force or a piezoelectric effect, for example. FIG. 20shows an example in which the diaphragm 181 is vibrated by electrostaticforce. Reference numerals 182 and 183 denote electrodes. The dottedlines show the vibrator 181 as deformed. In response to the vibration ofthe diaphragm 181, two valves 184 and 185 are opened or closed to sendthe fluid 161 from the right toward the left in the figure. For example,two micropumps 180 may be used as shown in FIG. 19 (in FIG. 19, themicropumps 160 correspond to the micropumps 180).

FIG. 21 shows an example of a variable mirror 188 using the fluid pump180. A reflecting membrane 189 is deformed into either a concave orconvex shape according to the amount of fluid 161, thereby functioningas a variable mirror.

FIG. 22 shows an example of a variable-focus lens 190 that is deformedby a piezoelectric effect. The variable-focus lens 190 comprises twovariable-focus lens elements 190A and 190B. The variable-focus lenselements 190A and 190B are connected with each other through a flowpath, e.g. a pipe, so that the fluid 161 is movable between the two lenselements 190A and 190B. Voltages with opposite signs are applied to therespective elastic materials 164 of the variable-focus lens elements190A and 190B so that the elastic materials 164 are deformed in oppositedirections to each other. Accordingly, the fluid reservoir 168 is notnecessary. In this point, the illustrated example is superior.

The variable-focus lens 190 arranged as shown in FIG. 22 allows twovariable-focus lens elements 190A and 190B to be implementedsimultaneously. The variable-focus lens 190 is suitable for use in azoom lens system, an optical system demanded to provide a wide focusingrange, a variable-magnification optical system, etc. FIG. 22 shows anexample of a zoom image pickup system (for digital cameras andcamcorders) in which the variable-focus lens elements 190A and 190B arecombined with a solid-state image pickup device 8. It is a matter ofcourse that the driving method is not necessarily limited to thepiezoelectric effect. For example, electrostatic force orelectromagnetic force may be used to drive the variable-focus lenselements 190A and 190B. Alternatively, a different driving method may beused for only either one of the variable-focus lens elements 190A and190B. Alternatively, reflecting membranes may be provided on therespective surfaces of the elastic materials 164 to form two variablemirrors. The arrangement may also be such that one of the two elementsforms a variable mirror and the other forms a variable-focus lens.

The basic idea of this embodiment is that a fluid 161 used for the samepurpose is shared among a plurality of variable-optical-characteristicoptical elements. The idea is also applicable to a combination of threeor more variable-optical-characteristic optical elements. It is alsopossible to use a jelly-like substance in place of the fluid, as in thecase of the example shown in FIG. 17.

Incidentally, variable mirrors, variable-focus lenses, etc. usingelectrostatic force or a piezoelectric effect may require a high voltagefor driving. In such a case, a step-up transformer or a piezoelectrictransformer should preferably be used. It is particularly preferable touse a laminated piezoelectric transformer from the viewpoint ofachieving a compact size.

FIG. 23 is a diagram showing an example ofvariable-optical-characteristic optical elements. The figure shows anexample of a variable mirror 195 using a magnetostrictive material. Amembrane 196 is made of a magnetostrictive material. A reflectingmembrane 197 (e.g. aluminum) is provided on the membrane 196. When anelectric current is passed through coils 198, a magnetic field isapplied to the membrane 196, causing the membrane 196 to be deformed.The membrane 196 can be deformed into either a convex surface or aconcave surface by changing the direction of the electric current. Thisarrangement has the merit of requiring no high voltage. It is alsopossible to deform the membrane 196 into various shapes by providing aplurality of coils 198 and varying electric currents supplied to thecoils 198. Examples of preferable magnetostrictive materials are cobalt,nickel, alfer, cadmium, iron-aluminum alloy, iron-silicon alloy,nickel-chromium alloy, nickel-vanadium alloy, iron-cobalt alloy,nickel-cobalt alloy, spinel ferrite, garnet ferrite, and supermagnetostrictive alloy. The arrangement may be such that that themembrane 196 made of a magnetostrictive material is formed from aferromagnetic material, and the membrane 196 is deformed by magneticforce acting between the membrane 196 and the coils 198. Examples offerromagnetic materials usable include iron and cobalt. It should benoted that reference numeral 165 in FIG. 23 denotes a transparent memberfor protecting the variable mirror 195. In particular, the transparentmember 165 has the effect of protecting the surface of the reflectingmembrane 197. It should be noted that the transparent member 165 may bea lens.

FIG. 24 is a diagram showing an example ofvariable-optical-characteristic optical elements. The figure shows anexample of a variable-focus lens 201 using a piezoelectric material 200.As the piezoelectric material 200, a material similar to the transparentsubstance 143 is usable. The piezoelectric material 200 is provided on atransparent soft substrate 202. As the substrate 202, it is desirable touse a synthetic resin material or an organic material. When a voltage isapplied to the piezoelectric material 200 through transparent electrodes59, the piezoelectric material 200 is deformed. In FIG. 24, the opticalelement has a convex lens action. The arrangement may be as follows. Thesubstrate 202 is formed in a convex shape in advance, and the size of atleast one of the two transparent electrodes 59 is made different fromthe size of the substrate 202. That is, one transparent electrode 59 ismade smaller than the substrate 202 as shown in FIG. 25, by way ofexample. With this arrangement, when the supply of the voltage is cutoff, or when the voltage is lowered, the other transparent electrode 59is concavely deformed at only a certain portion thereof, as shown inFIG. 25. Consequently, the optical element has a concave lens action andoperates as a variable-focus lens. At this time, the substrate 202 isdeformed in such a manner that the volumetric capacity of the fluid 161will not change. Therefore, the illustrated example has the merit ofdispensing with the fluid reservoir 168. In this example, a part of thesubstrate 202 retaining the fluid 161 is deformed by the piezoelectricmaterial 200 to dispense with the fluid reservoir 168. This is a greatadvantage of this example.

It should be noted that the transparent member 142 and the transparentsubstrate 163 may be lenses or plane-parallel plates. This is true ofthe examples shown in FIGS. 1, 2, 17 and 19.

FIG. 26 is a diagram showing an example ofvariable-optical-characteristic optical elements. The figure shows anexample of a variable-focus lens using two thin films 200A and 200B madeof a piezoelectric material. The illustrated example has the merit ofincreasing the amount of deformation to obtain a large variable focusrange by inverting the directional properties of the materials of thethin films 200A and 200B. Reference numeral 204 denotes a lens-shapedtransparent substrate. In this example also, the right-hand transparentelectrode 59 in the figure is formed smaller in size than the substrate202. It should be noted that the thickness of each of the substrate 202and the piezoelectric materials 200, 200A and 200B may be madenonuniform so as to control the way in which deformation takes placewhen a voltage is applied. With this arrangement, it is also possible toperform aberration correction for the lens, advantageously.

FIG. 27 is a diagram showing an example of variable-focus lenses. Thefigure shows a variable-focus lens 207 using an electrostrictivematerial 206, e.g. silicone rubber, or acrylic elastomer. When theapplied voltage is low, the lens operates as a convex lens as shown inFIG. 27. When the applied voltage is raised, as shown in FIG. 28, theelectrostrictive material 206 elongates vertically and contracts in thehorizontal direction as viewed in the figure. As a result, the focallength increases. Accordingly, the lens operates as a variable-focuslens. The illustrated example does not require a large electric currentand is therefore advantageous in that the power consumption is small.

FIG. 29 is a diagram showing an example ofvariable-optical-characteristic optical elements. The figure shows anexample of a variable-focus lens 214 using a photomechanical effect.Transparent elastic materials 208 and 209 sandwich azobenzene 210therebetween. The azobenzene 210 is irradiated with ultraviolet lightthrough transparent spacers 211. Reference numerals 212 and 213 denoteultraviolet light sources having center wavelengths λ₁ and λ₂,respectively, which are, for example, ultraviolet LEDs or ultravioletsemiconductor lasers. When trans-form azobenzene shown in part (A) ofFIG. 30 is irradiated with ultraviolet light of λ₁, it changes intocis-form azobenzene shown in part (B) of FIG. 30, resulting in areduction in the volumetric capacity of the azobenzene 210. Accordingly,the configuration of the variable-focus lens 214 thins. Thus, the convexlens action weakens. When the azobenzene 210 is irradiated withultraviolet light of λ₂, it changes from the cis form to the trans form,resulting in an increase in the volumetric capacity of the azobenzene210. Consequently, the convex lens action increases. In this way, thelens 214 operates as a variable-focus lens. Ultraviolet light is totallyreflected at the interface surface between air and each of thetransparent elastic materials 208 and 209. Therefore, no light will leakto the outside. Accordingly, the variable-focus lens 214 can operateefficiently.

Variable-focus lenses driven by the photomechanical effect are suitablefor use in variable-focus eyeglasses or the like, and they are alsosuitably used as contact lenses. The variable-focus lenses areconveniently used as contact lenses because the focal length of eachcontact lens in use can be changed in non-contact manner.

Next, embodiments of optical apparatus using the foregoingvariable-optical-characteristic optical elements will be shown.

FIG. 31 is a schematic view showing an example of an image pickup systemusing a variable mirror 9 according to a further embodiment of thepresent invention, for example, an image pickup system for use in adigital camera attached to a portable telephone, a capsule endoscope, avideo endoscope, a digital camera for a personal computer, a digitalcamera for a PDA, etc.

The image pickup system according to this embodiment has a variablemirror 9, a lens 102, a solid-state image pickup device 8 and a controlsystem 103 arranged to form a single image pickup unit 141. In the imagepickup unit 141 of this embodiment, light from an object passing throughthe lens 102 is collected by the variable mirror 9 to form an image onthe solid-state image pickup device 8. The variable mirror 9 is a kindof variable-optical-characteristic optical element and also known as“variable-focus mirror”.

According to this embodiment, even when the object distance has changed,focusing can be effected by deforming the variable mirror 9 without theneed to drive the lens by a motor or the like. Therefore, thisembodiment is excellent in that it is possible to achieve a compact andlightweight structure and a reduced power consumption. The image pickupunit 141 is usable as an image pickup system in any of the embodimentsof the present invention.

It should be noted that FIG. 31 shows a structural example of a controlsystem including a transformer booster circuit using a coil in thecontrol system 103. It is particularly preferable to use a laminatedpiezoelectric transformer from the viewpoint of achieving a compactsize. The booster circuit is usable in any of variable mirrors andvariable-focus lenses that use electricity in the present invention. Thebooster circuit is particularly useful in variable mirrors andvariable-focus lenses that use electrostatic force or a piezoelectriceffect.

FIG. 32 shows an example of variable-focus eyeglasses 302 usingvariable-focus lenses 301. As the variable-focus lenses 301, it ispossible to use variable-focus lenses using a liquid crystal in additionto the variable-focus lens 62 in FIG. 1, the variable-focus lens 56 inFIG. 2, the variable-focus lens 140 in FIG. 17, and the variable-focuslens 162 in FIG. 19, which have already been described.

In conventional variable-focus eyeglasses, a cord for power supply isneeded, which is bothersome in most cases. In this regard, thevariable-focus eyeglasses according to the present invention aresupplied with electric power by radio without using a cord, therebyimproving the ease of use. Let us describe the method of supplyingelectric power. As shown in FIG. 33, an electromagnetic wave is used tosupply electric power. The user wears a power transmitting unit 303 byhanging it from his/her neck, for example. The power transmitting unit303 may be put in a clothes pocket or the like. Alternatively, the powertransmitting unit 303 may be placed somewhere around the user (e.g. on adesk). In the power transmitting unit 303, a transmitting circuit 305 isdriven by power from a power supply 304 (e.g. a battery) to send anelectromagnetic wave from a transmitting antenna 306 toward thevariable-focus eyeglasses 302. The variable-focus eyeglasses 302 have areceiving antenna 307 provided on eyeglass frames 308 to receive theelectromagnetic wave sent from the power transmitting unit 303. Thereceived electromagnetic wave is, for example, boosted in voltage andrectified to drive the variable-focus lenses 140, 56, etc. When thevariable-focus lenses 162 or the like are used, the receivedelectromagnetic wave does not always need to be rectified.

It should be noted that the receiving antenna 307 may be made of atransparent electrically conductive material and provided in eachvariable-focus lens 301. Alternatively, a receiving antenna 307 made ofan electrically conductive material may be disposed around eachvariable-focus lens 301 or in a part thereof.

The power transmitting unit 303 or the power supply 304 may be sharedwith other equipment, e.g. a portable telephone, a portable audiosystem, or a notebook computer. If a microwave is used as theelectromagnetic wave, a high degree of transmission efficiency isavailable. The electromagnetic wave sent from the transmitting antenna306 should preferably be radiated strong in a specific direction in theform of a beam 309. By doing so, the electromagnetic wave can be sentwithout wasteful energy consumption, and the influence on otherelectronic equipment is minimized. It is preferable that theelectromagnetic wave should be radiated strong upwardly as shown in FIG.33.

Reference numeral 314 denotes a touch switch. Touching the switch 314lightly with a finger or the like allows the refractive power of thevariable-focus lenses 301 to be changed from one to another or permitsON-OFF switching of electricity. It is preferable to arrange the touchswitch 314 so that it operates cyclically according to the number oftimes at which the switch 314 is touched. By doing so, for example, thedistance at which the variable-focus eyeglasses 302 are focused can beswitched simply by changing the number of times at which the usertouches the switch 314 as follows: near point→middle point→farpoint→near point→middle point→far point . . . ; or near point→farpoint→near point→far point . . . . This is convenient.

Further, reference numeral 316 denotes an angle sensor, e.g. a gyro. Thevariable-focus eyeglasses 302 may be arranged, for example, such thatwhen the user looks down, the variable-focus eyeglasses 302 are focusedon the near point, whereas when the user looks up or faces horizontally,the variable-focus eyeglasses 302 are focused on the far point. Withthis arrangement, control similar to autofocusing can be effected, whichis convenient.

FIG. 34 is a diagram showing an example of variable-focus eyeglasses 302using the variable-focus lens 207. The variable-focus lens 207 issandwiched between transparent substrates or lenses 310 and 311 so as tobe protected. In addition, a part of the variable-focus lens 207 issecured to the transparent substrate or lens 310. By doing so, thevariable-focus lens 207 can be secured without interfering with theexpansion and contraction of the electrostrictive material 206 (FIG.27).

FIG. 35 is a diagram showing an example of the present invention. Thefigure shows an optical system 321 for a zoom digital camera that uses avariable mirror 320. A lens unit 322 comprising a concave lens is fixed,whereas a lens unit 323 and a lens unit 324 are movable. The lens units323 and 324 are movable along the optical axis direction as shown by thearrows to effect zooming. Meanwhile, the variable mirror 320 operatesfor focusing. Because the response is fast, the variable mirror 320 isusable for contrast-detection type autofocusing. In thecontrast-detection type autofocusing, the high-frequency component ofeach of images picked up while being defocused is examined, and theposition where the high-frequency component reaches a maximum is decidedto be an in-focus position. If the user performs zooming by hand, themotor becomes unnecessary. Accordingly, it is possible to obtain anautofocus zoom digital camera with minimal power consumption. It shouldbe noted that reference numeral 325 in the figure denotes a stop.

The optical system 321 for a zoom digital camera is also usable in otherelectronic image pickup systems, e.g. TV cameras and camcorders. As thevariable mirror, any of the variable mirrors described in thisapplication can be used. It is particularly preferable to use thevariable mirrors using electrostatic force, electromagnetic force, apiezoelectric effect or magnetostriction from the viewpoint of the fastresponse.

In the example shown in FIG. 35, the solid-state image pickup device 8should preferably be placed so that the short sides of the rectangularimage pickup area extend in the vertical direction as viewed in FIG. 35.The reason for this is as follows. Because the image height is small,asymmetric components of aberrations produced by the variable mirror 320become small. That is, the short-side direction of the image pickup area(which may be not only rectangular but also elliptical or polygonal)should preferably be approximately parallel, more precisely, within 40°,to the optical axis incidence plane of the variable mirror.

In a case where a variable mirror, a variable-focus lens, etc. are usedfor focusing, zooming or the like of an optical system, it is preferableto store the amount of deformation or the amount of change in the focallength, together with the amount of aberration correction, of such avariable-optical-characteristic optical element in a memory in the formof a look-up table or the like in correspondence to the object distance,the field angle in zooming, etc. By doing so, the operation of focusing,zooming, etc. is facilitated. When there is a change in the objectdistance or the field angle, the look-up table is referenced, and thevariable-focus lens or the variable mirror is deformed into a shape thatprovides a given focal length.

FIG. 36 is a diagram showing an example of the present invention. Thefigure shows a zoom optical system 327 using a variable-focus lens 326in place of the variable mirror used in FIG. 35. The variable-focus lens326 is used for focusing. Zooming is performed by moving lens units 323and 324 with a hand. The use application and effect of the zoom opticalsystem 327 are approximately the same as those of the optical system 321shown in FIG. 35. The zoom optical system 327 further has an advantagein that the mechanical design of the optical product is easy because theconstituent elements of the optical system are arranged in a straightline. As the variable-focus lens 326, it is possible to use avariable-focus lens using a liquid crystal in addition to thevariable-focus lenses described in this application. The lens units 323and 324 may be moved with a motor, a solenoid or the like instead ofmoving them by hand.

FIG. 37 is a diagram showing an example of the present invention, whichis a schematic view of an electronic image pickup apparatus using avariable mirror 240. In the electronic image pickup apparatus 241according to this embodiment, a free-form surface prism 242 is formed sothat an optical path is bent in the plane of the figure and also bent ina direction perpendicular to the plane of the figure (i.e. toward thereverse side of the plane of FIG. 37), thereby allowing the thickness Aof the electronic image pickup apparatus 241 to be reducedadvantageously. That is, in the free-form surface prism 242, theentering optical axis and the exiting optical axis are in a skewrelation to each other. In FIG. 37, reference numeral 243 denotes a lenswhose lens surface may be a rotationally symmetric surface or afree-form surface. It is preferable that the optical surfaces of thevariable mirror 240, the free-form surface prism 242 and the lens 243should be formed into extended curved surfaces. It should be noted thatthe electronic image pickup apparatus 241 in this embodiment is alsousable in a card-type digital camera.

Let us describe the variable mirror 240 in detail. A reflecting surface245 of the variable mirror 240 can be deformed into various shapes byapplying different voltages to electrodes 244 of the variable mirror240. For example, the reflecting surface 245 is deformed so as toperform focusing, zooming, etc. by directing the reflected optical axisto the position for image formation. However, the reflecting surface 245can also be deformed so that the direction of the reflected optical axisdiffers from the direction for image formation to a considerable extent,as shown in FIG. 38 by way of example. Thus, the incident light can bereturned substantially along the direction of incidence of the light,thereby reducing the amount of light incident on the solid-state imagepickup device 8. Consequently, the electronic image pickup apparatus 241operates as a shutter or a stop. Therefore, a conventional mechanicalshutter can omitted. In other words, the electronic image pickupapparatus 241 in this embodiment also has the function of controllingthe amount of light, advantageously.

It should be noted that the variable mirror 240 may be combined with amicropump 160, as shown in FIG. 39. That is, the variable mirror 240 maybe arranged such that the reflecting surface 245 is deformed into aconvex surface by using the micropump 160 so as to diverge light toobtain effects similar to the above.

Variable-focus lenses can also be arranged to serve also as a shutter ora stop, in addition to the variable mirrors.

FIG. 40 is a schematic view showing an embodiment of a variable-focuslens also serving as a shutter or a stop. The variable-focus lensaccording to this embodiment has a piezoelectric material 250. When ahigh voltage is applied thereto, the piezoelectric material 250 forms astrong concave surface to diverge a light beam, thereby substituting fora shutter or a stop.

The above-described operation of controlling or reducing the amount oflight in the variable mirrors and variable-focus lenses shouldpreferably be carried out during the charger transfer operation of thesolid-state image pickup device 8. By doing so, the operation can beperformed without causing blooming, advantageously. These operations ofvarying the amount of light are based on changes in the light-deflectingcharacteristics of the variable-optical-characteristic optical elements.

FIG. 41 is a diagram showing an example of the present invention. Thefigure shows an example of a vehicle-mounted video camera 222 (i.e. a TVcamera adapted for being mounted on an automobile) using twovariable-optical-characteristic optical elements (variable mirrors inthis example) 220 and 221 operated by different driving methods. In thefigure, reference numeral 223 denotes a TV monitor, and referencenumeral 224 denotes an electronic circuit. Reference numeral 227 denotesa stop. Two free-form surface prisms 225 and 226 and twovariable-optical-characteristic optical elements 220 and 221 form avariable-field-angle and autofocus optical system. Thevariable-optical-characteristic optical element 220 is driven byelectrostatic force and hence exhibits fast response. Therefore, theoptical element 220 performs autofocusing. On the other hand, thevariable-optical-characteristic optical element 221 has a slow responsespeed but is deformable to a considerable extent and hence used to varythe field angle or to change the viewing direction. By usingvariable-optical-characteristic optical elements driven by differentdriving methods for different functions in this way, an even moreconvenient optical apparatus can be realized. Thevariable-optical-characteristic optical element 221 is a variable mirrordriven by a fluid.

The mutually opposing surfaces of the variable mirrors 220 and 221 andoptical elements (free-form surface prisms in this example) 225 and 226,which face the variable mirrors 220 and 221, respectively, are concavesurfaces. With this arrangement, the angle of incidence of light rays onthe variable mirrors 220 and 221 can be minimized. This is advantageousfrom the viewpoint of aberration correction. In FIG. 41, referencenumeral 145 denotes a transparent electrode. Formation of thetransparent electrode 145 on the concave surface of the free-formsurface prism 225 is advantageous in that the reflecting membrane 228can also be deformed into a strong convex surface. Such a method ofsetting a transparent electrically conductive member, e.g. a transparentelectrode, can also be used for mirrors using electromagnetic force,magnetostriction, a piezoelectric effect, etc.

FIG. 42 is a diagram showing the video camera 222 as mounted on anautomobile 230. The figure shows an example in which the video camera222 is used as a TV camera for monitoring cars behind the automobile230. The figure also shows an example in which the video camera 222 isused as a mobile video telephone mounted near a dashboard 231. Thevehicle-mounted video camera 222 may be mounted in a car navigationsystem or a car audio system.

FIG. 43 shows an example in which the video camera 222 is mounted on aremote controller 233 for a television 232, e.g. a BS digital TV, aground wave digital TV, or a cable TV. The video camera 222 allows theuser's face, for example, to be sent by two-way communications using adigital TV. This is convenient. The video camera 222 should preferablybe used in a cordless remote controller, e.g. a remote controller for astereo, or a remote controller for a game machine, from the viewpoint oflow-power consumption.

FIG. 44 is a diagram showing an example of a viewfinder type displayapparatus 803 using variable mirrors 801 and 802. Because two variablemirrors 801 and 802 are used, it is possible to effect zooming, diopteradjustment, magnification change, etc. without moving a lens. Therefore,the viewfinder type display apparatus 803 is convenient. In the figure,reference numerals denote constituent elements as follows: 804 denotes alens; 805 denotes a display device (e.g. a liquid crystal displaydevice, or an organic EL); 806 denotes a backlight; 807 denotes anelectronic circuit; 808 denotes a notebook personal computer; 809denotes a screen; and 814 denotes a window of the viewfinder typedisplay apparatus. It should be noted that a variable-focus lens 810 maybe provided in place of the variable mirror 801 or 802. It is possibleto realize zooming, diopter adjustment, magnification change, etc. aslong as there are at least two variable-optical-characteristic opticalelements. It should be noted that as the variable mirrors 801 and 802and the variable-focus lens 810, it is possible to use the variablemirrors, the variable-focus lenses, etc. in the other embodiments of thepresent invention and those stated in the foregoing description.

The above-described viewfinder type display apparatus 803 can be used,as shown in FIG. 45, in a PDA (portable information terminal) 815, aportable telephone, a portable personal computer, an HMD (Head-MountedDisplay), etc. The viewfinder type display apparatus 803 may also beused as a viewfinder for a digital camera, a VTR camera, etc. In theexamples shown in FIGS. 42 and 43, it is also possible to use theoptical system 321 for a zoom digital camera (FIG. 35), the zoom opticalsystem 327 (FIG. 36), the variable-focus lens 190 (FIG. 22), the imagepickup unit 141 (FIG. 17), etc. beside the video camera 222, as a matterof course.

The following is a description of an embodiment of a digital camera asan example of optical apparatus to which avariable-optical-characteristic optical element according to the presentinvention is applicable.

FIG. 46 is a fragmentary perspective view showing a digital cameraaccording to an embodiment of the optical apparatus of the presentinvention that is in one state of being used for photography. FIG. 47 isa perspective view showing the digital camera according to theembodiment that is in another state of being used for photography.

Examples of the optical apparatus according to the present inventioninclude a digital camera system capable of taking and displaying animage, which comprises a card-type digital camera 71 capable of takingan image alone and having no display apparatus, as shown in FIG. 46, anda casing 73 having a display apparatus 72 and connectable with thecard-type digital camera 71, as shown in FIG. 47.

It should be noted that reference numerals in FIG. 46 denote constituentelements as follows: 74 denotes a shutter button; 75 denotes an opticalfinder; 76 denotes a photographer's eye; 77 denotes a subject; 78denotes an image pickup system; and 79 denotes contacts for electricalconnection with the casing. Reference numeral 80 in FIG. 47 denotes aflash provided on the casing to face toward the object plane.

According to this embodiment, images can be taken by using the card-typedigital camera 71 singly as a digital camera for imaging only. Further,the card-type digital camera 71 can be accommodated in the casing 73 andcan take an image in the accommodated state. In this case, the takenimage can be viewed on the display apparatus 72. Accordingly, when thedisplay apparatus 72 is not necessary, the card-type digital camera 71alone can be used as a lightweight digital camera to take images. Whenthe display apparatus 72 is necessary, the card-type digital camera 71can be used in combination with the casing 73.

According to this embodiment, even when the definition of solid-stateimage pickup devices to be built in digital cameras becomes higher astechnology progresses, it is only necessary to change the card part toan upgraded one. Thus, it is possible to keep the whole system frombecoming obsolescent.

This will be explained below with reference to FIG. 48. FIG. 48 is adiagram showing a system of optical apparatus according to the presentinvention that is applicable to this embodiment.

In this system, an optical apparatus can be constructed by combiningtogether a card and a casing respectively selected from a group of cardsshown in the left-hand part of FIG. 48 (i.e. a wide-angle lens card 71,a standard lens card 71 ₀₄, a telephoto lens card 71 ₀₅, a zoom lenscard 71 ₀₆, a close-up lens card 71 ₀₇, a compound-eye thin type card 71₀₃, a stereo lens card 71 ₀₈, a VTR camera card 71 ₀₉, a TV and FM card71 ₀₂, a BS digital card 71 ₁₀, a navigation card 71 ₁₁, a portabletelephone card 71 ₁₂, an AUDIO card 71 ₁₃, a high-definition card 71 ₀₁,a MOS card 71 ₁₄, a solar battery card 71 ₁₅, a wide-angle lens andAUDIO card 71 ₁₆, and a wide-angle lens and battery card 71 ₁₇) and agroup of casings shown in the right-hand part of FIG. 48 (i.e. an LCDcasing 73, a high-definition LCD casing 72 ₀₁, an LCD and speaker casing72 ₀₂, a paper display casing 72 ₀₅, an organic EL casing 72 ₀₆, a solarbattery casing 72 ₀₇, an additional battery casing 72 ₀₃, a frontconversion lens casing (close-up, wide-angle, and telephoto) 72 ₀₈, anadditional memory casing 72 ₀₉, a PDA (Personal Digital Assistant)casing 72 ₁₀, a TV and BS digital casing 72 ₁₁, a portable personalcomputer casing 72 ₁₂, a radio casing 72 ₀₄, a portable telephone casing72 ₁₃, and a data transfer casing 72 ₁₄). It should be noted that eachof the cards and casings is arranged to be capable of functioning alone.

FIG. 48 shows various embodiments in which a “card” and a “casing” canbe combined together.

The card-type digital camera 71 according to this embodiment correspondsto one of the cards (in FIG. 48, it corresponds to the wide-angle lenscard). The casing 73 corresponds to one of the casings (in FIG. 48, itcorresponds to the LCD casing).

When the definition of solid-state image pickup devices to be built incard-type digital cameras has become higher, a card-type digital camera71 ₀₁ having a high-definition solid-state image pickup device andcapable of being combined with the existing casings should be newlyproduced. In such a case, the user needs to buy only the high-definitioncard-type digital camera 71 ₀₁. By doing so, the user can use the casing73 in combination with the high-definition card-type digital camera 71₀₁. Accordingly, the cost is lower than in the case of buying ahigh-definition digital camera having an image pickup device and adisplay device fixedly mounted in a single box.

Conversely, when a high-definition LCD has been developed and becomeproducible at reduced costs, a casing (high-definition LCD casing) 72 ₀₁having a high-definition LCD (Liquid Crystal Display), which is shown inFIG. 48, should be developed. In such a case, the user needs to buy onlythe high-definition LCD casing 72 ₀₁. By doing so, the user can use thecard-type digital camera 71, 71 ₀₁, etc. in combination with thehigh-definition LCD casing 72 ₀₁. Accordingly, the cost is lower than inthe case of newly buying a digital camera with a high-definition LCD.

It should be noted that in FIG. 48 the devices referred to as “xx cards”(71 and 71 _(n), where n represents numbers 01, 02 . . . ) each have animage pickup system incorporated therein in principle and are thereforecapable of taking images alone. Further, the devices include functionsdesignated by their names.

Further, the devices referred to as “xx casings” (73 and 72 _(n), wheren represents numbers 01, 02 . . . ) each have a display deviceincorporated therein in principle and are arranged to perform functionsdesignated by their names.

However, among the above-described cards, those which can function alonewithout an image pickup function may be arranged without an image pickupsystem. For example, the TV and FM card 71 ₀₂ falls under this category.The TV and FM card 71 ₀₂ is arranged to have the function of receivingvarious kinds of broadcasting, i.e. TV, FM, and AM. By combining the TVand FM card 71 ₀₂ with the LCD and speaker casing 72 ₀₂, for example, itis possible to watch TV images with sound.

Casings that can function alone without a display apparatus, e.g. theadditional battery casing 72 ₀₃, may be arranged without a displayapparatus. The additional battery casing 72 ₀₃ is a casing arranged tosupply an additional battery power so that a long-time image pickupoperation can be realized by combination with a card. The solar batterycasing 72 ₀₇ is also a casing arranged to supply an electric currentthrough a solar battery.

Some casings can function alone without being combined with a card, asin the case of the radio casing 72 ₀₄. The radio casing 72 ₀₄ isarranged to function alone as a radio for receiving FM, AM or SWsignals.

Casings equipped with a display apparatus may be arranged to have apaper display capable of wrapping each card. The paper display casing 72₀₅ functions as a display apparatus and also serves to protect the cardfrom an external shock like a leather or cloth casing for a conventionalcamera.

FIG. 49 shows the way in which the paper display casing 72 ₀₅ and thecard-type digital camera 71 are combined together.

The paper display casing 72 ₀₅ is arranged to be capable of takingimages in the state of accommodating the card-type digital camera 71therein.

It should be noted that, in FIG. 49, reference numeral 82 denotes apaper display. Reference numeral 83 denotes a convex button, andreference numeral 84 denotes a concave button. By fitting the buttons 83and 84 to each other, the accommodated card 71 can be secured so as notto jump out of the paper display casing 72 ₀₅.

Each of the cards and casings shown in FIG. 48 may be arranged so thatit can be connected directly to a personal computer.

With the above-described arrangement, it is possible to performprocessing, storage, transfer, etc. of images, characters, sound, powersupply, etc. through the personal computer.

In the example of the digital camera shown in FIGS. 46 and 47, theconnection of a card and a casing has been described with regard to anarrangement based on the assumption that the card and the casing areconnected together through mechanical contacts. It should be noted,however, that the present invention is not necessarily limited to thedescribed arrangement. The arrangement may be such that a card and acasing are connected together by connection through a cable, or opticalcommunication connection using light (infrared), or wireless connection,e.g. Bluetooth.

The compound-eye thin type card 71 ₀₃ is a card-type digital cameraarranged so that the card is particularly thin in thickness. Thethickness is reduced by using a compound eye in the image pickup system.

FIG. 50 is a diagram illustrating an embodiment of a compound-eye thintype card. The compound-eye thin type card 71 ₀₃ in this embodiment hasfour lenses 85 placed on the object side of a solid-state image pickupdevice 8 in the card in such a manner that the lenses 85 are in closeproximity to the solid-state image pickup device 8. In FIG. 50, however,two lenses on the reverse side of the plane of the figure are hidden bythe other two lenses.

According to the compound-eye thin type card 71 ₀₃ of this embodiment,four divided inverted images are formed on the solid-state image pickupdevice 8 through the lenses 85. The four divided inverted images areconnected together into one image by image processing executedthereafter through an image processing device, e.g. a personal computer,thereby obtaining an image similar to that obtained by using a cardcontaining a conventional optical system.

The lens arrangement of the compound-eye thin type card 71 ₀₃ in thisembodiment is applicable to all the image pickup systems in the imagepickup apparatus and optical products according to the presentinvention. For example, it is usable in the image pickup system 78 shownin FIG. 46 and also usable in an image pickup system 78 shown in FIG. 52(described later).

FIG. 51 is a perspective view showing another embodiment of the opticalapparatus according to the present invention.

In the optical apparatus according to this embodiment, each “card” andeach “casing” constituting the system shown in FIGS. 46 to 48 are formedinto two box-shaped configurations, respectively. In FIG. 51, referencenumeral 91 denotes an image pickup box A, which has a function similarto that of the card-type digital camera 71 shown in FIGS. 46 to 48.Reference numeral 92 denotes a display box B, which has a functionsimilar to that of the casing 73 shown in FIGS. 46 to 48. Otherconstituent members in FIG. 51 that are similar to those shown in FIGS.46 and 47 are denoted by the same reference numerals, and a descriptionthereof is omitted.

It should be noted that the boxes A and B are connectable with eachother through screws, a bayonet coupling, etc. The box A is arranged tobe capable of taking images either alone or in the state of beingconnected with the box B.

The boxes A and B can be arranged in the form of a great variety ofboxes having functions equivalent to the “casings” and “cards” shown inFIG. 48.

FIG. 52 is a schematic view showing still another embodiment of theoptical apparatus according to the present invention. The opticalapparatus according to this embodiment is a portable telephone 100having an image pickup system 78. The image pickup system 78 shouldpreferably be arranged to include a variable-optical-characteristicoptical element as described above. The use of avariable-optical-characteristic optical element allows focusing orzooming to be effected with a lower power consumption than in the caseof moving the lenses by using a motor. As the image pickup system 78, itis possible to use the image pickup unit 141 in FIG. 31, the electronicimage pickup apparatus 241 in FIG. 37, or the variable-focus lens 190 inFIG. 22, by way of example. The image pickup system 78 including avariable-optical-characteristic optical element should preferably bearranged to be capable of focusing to take an image so that it ispossible to take a close-up of an object such as a flower or an insect.

It should be noted that the image pickup system 78 may be arranged as anexternal electronic image pickup apparatus, instead of providing it asan integral part of the portable telephone 100, so that the image pickupsystem 78 can be attached to the portable telephone 100 as an adapter.

The image pickup system 78 is also usable with a digital camera, a videotelephone, etc.

It is also possible to provide the image pickup system 78 in aconventional immobile telephone installed indoors.

Further, the image pickup system 78 may be used as an image input deviceor an information sending device by providing it in a BS digitaltelevision, a remote controller for a BS digital television, a gamemachine, a remote controller for a game machine, a mouse used with apersonal computer, a keyboard of a personal computer, a monitor of apersonal computer, etc.

If the image pickup system 78 having a variable-optical-characteristicoptical element is used in various apparatus such as those mentionedabove, the apparatus can be reduced in size, weight and powerconsumption, advantageously.

FIG. 53 is an illustration of variable-focus eyeglasses 302 using theabove-described variable-focus lenses 301 according to a furtherembodiment of the optical apparatus to which thevariable-optical-characteristic optical element of the present inventionis applicable.

As a person ages, the focus control action of his/her eyes becomes weak.However, the use of eyeglasses with the variable-focus lenses 301 makesit possible to see in-focus images throughout the object distance rangefrom the near point to the far point. This is very convenient.

It should be noted that the term “piezoelectric effect” as used in thisapplication shall include an electrostrictive effect.

Similarly, the term “piezoelectric material” shall includeelectrostrictive materials.

The image pickup apparatus using variable-optical-characteristic opticalelements stated in the description of the present invention shouldpreferably be provided in the following products or articles from theviewpoint of low power consumption, resistance to shock, compact andlightweight structure, and so forth:

The dashboard of an automobile; the instrument panel of an automobile; aW-CDMA (IMT-2000) (next-generation portable telephone); a player forDVD, CD, MD, etc.; a portable player for DVD, CD, MD, etc.; a car audiocontrol panel; a car navigation system; eyeglasses; variable-focuseyeglasses; an HMD (Head-Mounted Display); a TV; an HD-TV; a BS digitalTV; a notebook personal computer; a personal computer; a mouse; akeyboard; a PDA; a liquid crystal monitor; a home theater; a gamemachine; a headphone stereo; an audio system; a stereo amplifier; atuner; a cassette deck; a remote controller for DVD, CD, etc.; aspeaker; a bicycle; an automobile; a bus; a motorcycle; a motor scooter;a helmet; a streetcar; a train; an airplane; a boat; a ship; and soforth.

It should be noted that an image pickup apparatus having novariable-optical-characteristic optical element may be provided in theabove-described products. The reason for this is that it is moreconvenient than using a TV camera, a digital camera, etc. separately.

Finally, let us state the definition of each term used in the presentinvention.

The term “optical apparatus” means an apparatus including an opticalsystem or an optical element. The optical apparatus need not be capableof functioning alone. In other words, the optical apparatus may be apart of a system.

The optical apparatus include image pickup apparatus, viewing apparatus,display apparatus, illuminating apparatus, signal processing apparatus,etc.

Examples of image pickup apparatus are a film-with-lens camera, adigital camera, a robot's eye, an interchangeable-lens digitalsingle-lens reflex camera, a video camera, an animation recorder, anelectronic animation recorder, a camcorder, a VTR camera, and a videoendoscope.

Examples of viewing apparatus are a microscope, a telescope, eyeglasses,binoculars, a magnifier, a fiberscope, a finder, and a viewfinder.

Examples of display apparatus are a liquid crystal display, aviewfinder, a game machine (e.g. PlayStation, available from SonyCorporation), a video projector, a liquid crystal projector, ahead-mounted display (HMD), a PDA (portable information terminal), and aportable telephone.

Examples of illuminating apparatus are a flash of a camera, a headlightof an automobile, an endoscope light source, and a microscope lightsource.

Examples of signal processing apparatus are a portable telephone, apersonal computer, an optical disk read/write apparatus, and a computingunit of an optical computer.

The term “image pickup device” means, for example, a CCD, an imagepickup tube, a solid-state image pickup device, and a photographic film.Further, plane-parallel plates shall be included among prisms. Changesin the observer shall include a change in diopter. Changes in thesubject shall include a change in the distance to an object as asubject, a movement of the object, a motion and vibration of the object,a shaking of the object, etc.

It should be noted that all digital cameras, video cameras, VTR cameras,animation recording cameras, etc. are examples of electronic imagepickup apparatus.

The definition of “extended curved surfaces” is as follows.

The surfaces may have any configuration, e.g. a spherical surface, aplane surface, a rotationally symmetric aspherical surface, a sphericalsurface decentered with respect to an optical axis, a plane surfacedecentered with respect to an optical axis, a rotationally symmetricaspherical surface decentered with respect to an optical axis, anaspherical surface having planes of symmetry, an aspherical surfacehaving only one plane of symmetry, an aspherical surface having no planeof symmetry, a free-form surface, or a surface having non-differentiablepoints or lines. The surfaces may be any surfaces that can have someeffect on light, whether reflecting surfaces or refracting surfaces. Inthe present invention, these surfaces are generically called “extendedcurved surfaces”.

Free-form surfaces used in the present invention are defined by thefollowing equation. The Z-axis of the defining equation is the axis of afree-form surface.

$\begin{matrix}{Z = \frac{{cr}^{2}}{\left\lbrack {1 + {\sqrt{\;}\left\{ {1 - {\left( {1 + k} \right)c^{2}r^{2}}} \right\}}} \right\rbrack + {\sum\limits_{j = 2}^{66}{C_{j}X^{m}Y^{n}}}}} & (a)\end{matrix}$

In Eq. (a), the first term is a spherical surface term, and the secondterm is a free-form surface term.

In the spherical surface term:

-   -   c: the curvature at the vertex    -   k: a conic constant    -   r=√{square root over ( )}(X²+Y²)

The free-form surface term is given by

${\sum\limits_{j = 2}^{66}{C_{j}X^{m}Y^{n}}} = {{C_{2}X} + {C_{3}Y} + {C_{4}X^{2}} + {C_{5}{XY}} + {C_{6}Y^{2}} + {C_{7}X^{3}} + {C_{8}X^{2}Y} + {C_{9}{XY}^{2}} + {C_{10}Y^{3}} + {C_{11}X^{4}} + {C_{12}X^{3}Y} + {C_{13}X^{2}Y^{2}} + {C_{14}{XY}^{3}} + {C_{15}Y^{4}} + {C_{16}X^{5}} + {C_{17}X^{4}Y} + {C_{18}X^{3}Y^{2}} + {C_{19}X^{2}Y^{3}} + {C_{20}{XY}^{4}} + {C_{21}Y^{5}} + {C_{22}X^{6}} + {C_{23}X^{5}Y} + {C_{24}X^{4}Y^{2}} + {C_{25}X^{3}Y^{3}} + {C_{26}X^{2}Y^{4}} + {C_{27}{XY}^{5}} + {C_{28}Y^{6}} + {C_{29}X^{7}} + {C_{30}X^{6}Y} + {C_{31}X^{5}Y^{2}} + {C_{32}X^{4}Y^{3}} + {C_{33}X^{3}Y^{4}} + {C_{34}X^{2}Y^{5}} + {C_{35}{XY}^{6}} + {C_{36}Y^{7}}}$

where Cj (j is an integer of 2 or higher) are coefficients.

In general, the above-described free-form surface does not have planesof symmetry in both the XZ- and YZ-planes. However, a free-form surfacehaving only one plane of symmetry parallel to the YZ-plane is obtainedby making all terms of odd-numbered degrees with respect to X zero. Afree-form surface having only one plane of symmetry parallel to theXZ-plane is obtained by making all terms of odd-numbered degrees withrespect to Y zero.

In addition, free-form surfaces as the above-described surfaces with arotationally asymmetric curved surface configuration may be defined byZernike polynomials. That is, the configuration of a free-form surfacemay be defined by the following equation (b). The Z-axis of the definingequation (b) is the axis of Zernike polynomial. A rotationallyasymmetric surface is defined by polar coordinates of the height of theZ-axis with respect to the XY-plane. In the equation (b), A is thedistance from the Z-axis in the XY-plane, and R is the azimuth angleabout the Z-axis, which is expressed by the angle of rotation measuredfrom the Z-axis.

x=R×cos(A)

y=R×sin(A)

Z=D ₂ +D ₃ R cos(A)+D ₄ R sin(A)

+D₅R² cos(2A)+D₆(R²−1)+D₇R² sin(2A)

+D₈R³ cos(3A)+D₉(3R³−2R)cos(A)+D₁₀(3R³−2R)sin(A)+D₁₁R³ sin(3A)

+D₁₂R⁴cos(4A)+D₁₃(4R⁴−3R²)cos(2A)+D₁₄(6R⁴−6R²+1)+D₁₅(4R⁴−3R²)sin(2A)+D₁₆R⁴sin(4A)

+D₁₇R⁵ cos(5A)+D₁₈(5R⁵−4R³)cos(3A)+D₁₉(10R⁵−12R³+3R)cos(A)+D₂₀(10R⁵−12R³+3R)sin(A)+D₂₁ (5R⁵−4R³)sin(3A)+D₂₂R⁵ sin(5A)

+D₂₃R⁶cos(6A)+D₂₄(6R⁶−5R⁴)cos(4A)+D₂₅(15R⁶−20R⁴+6R²)cos(2A)+D₂₆(20R⁶−30R⁴+12R²−1)+D₂₇(15R⁶−20R⁴+6R²)sin(2A)+D₂₈(6R⁶−5R⁴)sin(4A)+D₂₉R⁶sin(6A)  (b)

where D_(m) (m is an integer of 2 or higher) are coefficients.

It should be noted that to design an optical system symmetric withrespect to the X-axis direction, D₄, D₅, D₆, D₁₀, D₁₁, D₁₂, D₁₃, D₁₄,D₂₀, D₂₁, D₂₂ should be used.

The above defining equations are shown to exemplify surfaces with arotationally asymmetric curved surface configuration. Therefore, thesame advantageous effects can be obtained for any other definingequation that expresses such a rotationally asymmetric curved surfaceconfiguration. The curved surface configuration may be expressed byother defining equations as long as they are mathematically equivalentto the above equation.

It should be noted that other examples of defining equations forfree-form surfaces include the following defining equation (c):

Z=ΣΣC_(nm)XY

Assuming that k=7 (polynomial of degree 7), for example, a free-formsurface is expressed by an expanded form of the above equation asfollows:

Z=C ₂ +C ₃ Y+C ₄ |X|

+C₅Y²+C₆Y|X|+C₇X²

+C₈Y³+C₉Y²|X|+C₁₀YX²+C₁₁|X³|

+C₁₂Y⁴+C₁₃Y³|X|+C₁₄Y²X²+C₁₅Y|X³|+C₁₆X⁴

+C₁₇Y⁵+C₁₈Y⁴|X|+C₁₉Y³X²+C₂₀Y²|X³|+C₂₁YX⁴+C₂₂|X⁵|

+C₂₃Y⁶+C₂₄Y⁵|X|+C₂₅Y⁴X²+C₂₆Y³|X³|+C₂₇Y²X⁴+C₂₈Y|X⁵|+C₂₉X⁶

+C₃₀Y⁷+C₃₁Y⁶|X|+C₃₂Y⁵X²+C₃₃Y⁴|X³|+C₃₄Y³X⁴+C₃₅Y²|X⁵|+C₃₆YX⁶+C₃₇|X⁷|  (c)

Aspherical surfaces used in the present invention are rotationallysymmetric aspherical surfaces given by the following equation:

Z=(Y ² /R)/[1+{1−(1+K)Y ² /R ²}^(1/2) ]+AY ⁴ +BY+CY ⁸ +DY ¹⁰+ . . .  (d)

In the above equation, Z is an optical axis (axial principal ray) forwhich the direction of travel of light is defined as a positivedirection, and Y is taken in a direction perpendicular to the opticalaxis. R is a paraxial curvature radius, K is a conic constant, and A, B,C, D . . . are 4th-, 6th-, 8th- and 10th-order aspherical coefficients,respectively. The Z-axis of this defining equation is the axis of therotationally symmetric aspherical surface.

The configuration of an anamorphic surface is defined by the followingequation. A straight line passing through the origin of the surfaceconfiguration perpendicularly to the optical surface is the axis of theanamorphic surface.

Z=(Cx·X ² +Cy·Y ²)/[1+{1−(1+Kx)Cx ² ·X ²−(1+Ky)Cy ² ·Y ²}^(1/2)]+ΣRn{(1−Pn)X ²+(1+Pn)Y ²}^((n+1))

Assuming that n=4 (polynomial of degree 4), for example, an anamorphicsurface may be expressed by an expanded form of the above equation asfollows:

Z=(Cx·X ² +Cy·Y ²)/[1+{1−(1+Kx)Cx ² ·X ²−(1+Ky)Cy ² ·Y ²}^(1/2)]

+R1{(1−P1)X ²+(1+P)Y ²}²

+R2{(1−P2)X²+(1+P2)Y²}³

+R3{(1−P3)X²+(1+P3)Y²}⁴

+R4{(1−P4)X²+(1+P4)Y²}⁵  (e)

where Z is the amount of deviation from a plane tangent to the origin ofthe surface configuration; Cx is the curvature in the X-axis direction;Cy is the curvature in the Y-axis direction; Kx is the conic coefficientin the X-axis direction; Ky is the conic coefficient in the Y-axisdirection; Rn is the rotationally symmetric component of the asphericalsurface term; and Pn is the rotationally asymmetric component of theaspherical surface term.

It should be noted that the radius of curvature Rx in the X-axisdirection and the radius of curvature Ry in the Y-axis direction arerelated to the curvatures Cx and Cy as follows:

Rx=1/Cx, Ry=1/Cy

Toric surfaces include an X-toric surface and a Y-toric surface, whichare defined by the following equations, respectively. A straight linepassing through the origin of the surface configuration perpendicularlyto the optical surface is the axis of the toric surface. The X-toricsurface is given by

F(X)=Cx·X ²/[1+{1−(1+K)Cx ² ·X ²}^(1/2) ]+AX ⁴ +BX ⁶ +CX ⁸ +DX ¹⁰ . . .

Z=F(X)+(½)Cy{Y ² +Z ² −F(X)²}  (f)

Then, the surface is rotated around the X-axis, passing through thecenter of curvature in the Y-direction. As a result, the surface becomesaspherical in the XZ-plane and circular in the YZ-plane.

The Y-toric surface is given by

F(Y)=Cy·Y ²/[1+{1−(1+K)Cy ² ·Y ²}^(1/2) ]+AY ⁴ +BY ⁶ +CY ⁸ +DY ¹⁰ . . .

Z=F(Y)+(½)Cx{X ² +Z ² −F(Y)²}  (g)

Then, the surface is rotated around the Y-axis, passing through thecenter of curvature in the X-direction. As a result, the surface becomesaspherical in the YZ-plane and circular in the XZ-plane.

In the above equations, Z is the amount of deviation from a planetangent to the origin of the surface configuration; Cx is the curvaturein the X-axis direction; Cy is the curvature in the Y-axis direction; Kis a conic coefficient; and A, B, C and D are aspherical coefficients,respectively. It should be noted that the radius of curvature Rx in theX-axis direction and the radius of curvature Ry in the Y-axis directionare related to the curvatures Cx and Cy as follows:

Rx=1/Cx, Ry=1/Cy

The term “variable-optical-characteristic optical element” includes avariable-focus lens, a variable mirror, a variable prism whose surfaceconfiguration is variable, a variable-apex angle prism, a prism whoselight-deflecting action is variable, variable diffractive opticalelements whose light-deflecting action is variable, i.e. a variable HOEand a variable DOD, and so forth.

The term “variable-focus lens” also includes a variable lens in whichthe focal length is invariable but the amount of aberration is variable.The same is the case with the term “variable mirror”.

In short, optical elements in which a light-deflecting action such asreflection, refraction, or diffraction, is changeable are called“variable-optical-characteristic optical elements”.

The term “information sending apparatus” means apparatus capable ofinputting and transmitting some information, e.g. a portable telephone,an immobile telephone, remote controllers for a game machine, atelevision, a radio-cassette player, a stereo, etc., a personalcomputer, a keyboard, a mouse, a touch panel, etc. for use with apersonal computer, and so forth.

The information sending apparatus shall also include a televisionmonitor with an image pickup apparatus, and a monitor and display foruse with a personal computer.

The information sending apparatus are included in the signal processingapparatus.

As has been stated above, it is possible according to present inventionto obtain optical apparatus, display apparatus, signal processingapparatus, image pickup apparatus, etc. that are compact, lightweight,inexpensive and capable of readily extending their capabilities.

1. A variable-optical-characteristic optical element characterized byusing a photomechanical effect.
 2. A variable-focus lens characterizedby using a photomechanical effect.
 3. A variable mirror characterized byusing a photomechanical effect.
 4. A variable-optical-characteristicoptical element characterized by having at least two different kinds oflight sources and using a photomechanical effect.